diff --git a/compiler/testData/asJava/lightClasses/StubOrderForOverloads.java b/compiler/testData/asJava/lightClasses/StubOrderForOverloads.java
index 0b0197b4edb..2c3a8ecba6e 100644
--- a/compiler/testData/asJava/lightClasses/StubOrderForOverloads.java
+++ b/compiler/testData/asJava/lightClasses/StubOrderForOverloads.java
@@ -1,7 +1,7 @@
 public final class A {
     public final void foo(@org.jetbrains.annotations.Nullable P p1, @org.jetbrains.annotations.Nullable P p2) { /* compiled code */ }
 
-    public final void foo(@org.jetbrains.annotations.NotNull kotlin.jvm.functions.Function4<? super RS,? super P,? super P,? super kotlin.coroutines.experimental.Continuation<? super kotlin.Unit>,? extends java.lang.Object> listener) { /* compiled code */ }
+    public final void foo(@org.jetbrains.annotations.NotNull kotlin.jvm.functions.Function4<? super RS,? super P,? super P,? super kotlin.coroutines.Continuation<? super kotlin.Unit>,? extends java.lang.Object> listener) { /* compiled code */ }
 
     public A() { /* compiled code */ }
-}
+}
\ No newline at end of file
diff --git a/compiler/testData/cli/jvm/progressiveModeOff.args b/compiler/testData/cli/jvm/progressiveModeOff.args
index cfe8ab049db..cca6bb66990 100644
--- a/compiler/testData/cli/jvm/progressiveModeOff.args
+++ b/compiler/testData/cli/jvm/progressiveModeOff.args
@@ -1,3 +1,5 @@
 $TESTDATA_DIR$/progressive
 -d
-$TEMP_DIR$
\ No newline at end of file
+$TEMP_DIR$
+-language-version
+1.2
diff --git a/compiler/testData/codegen/box/coroutines/debug/debuggerMetadata.kt b/compiler/testData/codegen/box/coroutines/debug/debuggerMetadata.kt
index 4642b37b5ec..35e682104fc 100644
--- a/compiler/testData/codegen/box/coroutines/debug/debuggerMetadata.kt
+++ b/compiler/testData/codegen/box/coroutines/debug/debuggerMetadata.kt
@@ -87,7 +87,7 @@ fun box(): String {
     builder {
         suspended()
     }
-    res = (continuation!! as BaseContinuationImpl).getSpilledVariableFieldMapping().toMap()["L$0"] ?: "suspended fail"
+    res = (continuation!! as BaseContinuationImpl).getSpilledVariableFieldMapping()!!.toMap()["L$0"] ?: "suspended fail"
     if (res != "ss") {
         return "" + res
     }
@@ -95,12 +95,12 @@ fun box(): String {
     builder {
         multipleLocalsInOneSlot()
     }
-    res = (continuation!! as BaseContinuationImpl).getSpilledVariableFieldMapping().toMap()["I$0"] ?: "multipleLocalsInOneSlot fail 1"
+    res = (continuation!! as BaseContinuationImpl).getSpilledVariableFieldMapping()!!.toMap()["I$0"] ?: "multipleLocalsInOneSlot fail 1"
     if (res != "first") {
         return "" + res
     }
     continuation!!.resumeWith(SuccessOrFailure.success(Unit))
-    res = (continuation!! as BaseContinuationImpl).getSpilledVariableFieldMapping().toMap()["I$0"] ?: "multipleLocalsInOneSlot fail 2"
+    res = (continuation!! as BaseContinuationImpl).getSpilledVariableFieldMapping()!!.toMap()["I$0"] ?: "multipleLocalsInOneSlot fail 2"
     if (res != "second") {
         return "" + res
     }
diff --git a/compiler/testData/codegen/box/enum/kt9711_2.kt b/compiler/testData/codegen/box/enum/kt9711_2.kt
index cc576aaf05f..bfe2465b506 100644
--- a/compiler/testData/codegen/box/enum/kt9711_2.kt
+++ b/compiler/testData/codegen/box/enum/kt9711_2.kt
@@ -1,5 +1,4 @@
 // TODO: muted automatically, investigate should it be ran for JS or not
-// IGNORE_BACKEND: JS
 
 enum class IssueState {
 
diff --git a/compiler/testData/codegen/box/inlineClasses/functionNameMangling/reflectionForPropertyOfInlineClassType.kt b/compiler/testData/codegen/box/inlineClasses/functionNameMangling/reflectionForPropertyOfInlineClassType.kt
index 675dda14e21..b4bb2896933 100644
--- a/compiler/testData/codegen/box/inlineClasses/functionNameMangling/reflectionForPropertyOfInlineClassType.kt
+++ b/compiler/testData/codegen/box/inlineClasses/functionNameMangling/reflectionForPropertyOfInlineClassType.kt
@@ -1,5 +1,5 @@
 // !LANGUAGE: +InlineClasses
-// IGNORE_BACKEND: JVM_IR, JS
+// IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 import kotlin.test.*
 
diff --git a/compiler/testData/codegen/box/unsignedTypes/kt25784.kt b/compiler/testData/codegen/box/unsignedTypes/kt25784.kt
index b22c18a1143..e265730e4cf 100644
--- a/compiler/testData/codegen/box/unsignedTypes/kt25784.kt
+++ b/compiler/testData/codegen/box/unsignedTypes/kt25784.kt
@@ -1,5 +1,5 @@
 // WITH_UNSIGNED
-// IGNORE_BACKEND: JVM_IR, JS_IR, JS
+// IGNORE_BACKEND: JVM_IR, JS_IR
 
 import kotlin.reflect.KProperty
 import kotlin.reflect.KProperty0
diff --git a/compiler/testData/codegen/bytecodeListing/inline/simpleNamed.txt b/compiler/testData/codegen/bytecodeListing/inline/simpleNamed.txt
index 2fe33969789..8be4b63ffe6 100644
--- a/compiler/testData/codegen/bytecodeListing/inline/simpleNamed.txt
+++ b/compiler/testData/codegen/bytecodeListing/inline/simpleNamed.txt
@@ -1,34 +1,34 @@
 @kotlin.Metadata
 public final class Foo {
     public method <init>(): void
-    private final method acceptsCrossinline(p0: kotlin.jvm.functions.Function0, p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final @org.jetbrains.annotations.Nullable method generic$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final @org.jetbrains.annotations.Nullable method generic$$forInline(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final @org.jetbrains.annotations.Nullable method generic(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final @org.jetbrains.annotations.Nullable method generic(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final method genericWithReified(p0: java.lang.Object, p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final method genericWithReified(p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private synthetic final method privateInline(p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final @kotlin.internal.InlineOnly method shouldNotHaveSuffix(p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
+    private final method acceptsCrossinline(p0: kotlin.jvm.functions.Function0, p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final @org.jetbrains.annotations.Nullable method generic$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    private final @org.jetbrains.annotations.Nullable method generic$$forInline(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    public final @org.jetbrains.annotations.Nullable method generic(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    public final @org.jetbrains.annotations.Nullable method generic(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final method genericWithReified(p0: java.lang.Object, p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final method genericWithReified(p0: kotlin.coroutines.Continuation): java.lang.Object
+    private synthetic final method privateInline(p0: kotlin.coroutines.Continuation): java.lang.Object
+    private final @kotlin.internal.InlineOnly method shouldNotHaveSuffix(p0: kotlin.coroutines.Continuation): java.lang.Object
+    private final @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    public final @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    public final @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
 }
 
 @kotlin.Metadata
 public final class SimpleNamedKt {
-    private final static method acceptsCrossinline(p0: kotlin.jvm.functions.Function0, p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final static @org.jetbrains.annotations.Nullable method generic$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final static @org.jetbrains.annotations.Nullable method generic$$forInline(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final static @org.jetbrains.annotations.Nullable method generic(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final static @org.jetbrains.annotations.Nullable method generic(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final static method genericWithReified(p0: java.lang.Object, p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final static method genericWithReified(p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private synthetic final static method privateInline(p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final static @kotlin.internal.InlineOnly method shouldNotHaveSuffix(p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final static @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    private final static @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final static @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.experimental.Continuation): java.lang.Object
-    public final static @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.experimental.Continuation): java.lang.Object
+    private final static method acceptsCrossinline(p0: kotlin.jvm.functions.Function0, p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final static @org.jetbrains.annotations.Nullable method generic$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    private final static @org.jetbrains.annotations.Nullable method generic$$forInline(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    public final static @org.jetbrains.annotations.Nullable method generic(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    public final static @org.jetbrains.annotations.Nullable method generic(p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final static method genericWithReified(p0: java.lang.Object, p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final static method genericWithReified(p0: kotlin.coroutines.Continuation): java.lang.Object
+    private synthetic final static method privateInline(p0: kotlin.coroutines.Continuation): java.lang.Object
+    private final static @kotlin.internal.InlineOnly method shouldNotHaveSuffix(p0: kotlin.coroutines.Continuation): java.lang.Object
+    private final static @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    private final static @org.jetbrains.annotations.Nullable method simple$$forInline(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    public final static @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.Unit, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    public final static @org.jetbrains.annotations.Nullable method simple(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
 }
diff --git a/compiler/testData/diagnostics/testsWithJsStdLib/native/inlineClassAsParameterOrReturnType.kt.txt b/compiler/testData/diagnostics/testsWithJsStdLib/native/inlineClassAsParameterOrReturnType.kt.txt
index 6c864e7c782..5d26a210a24 100644
--- a/compiler/testData/diagnostics/testsWithJsStdLib/native/inlineClassAsParameterOrReturnType.kt.txt
+++ b/compiler/testData/diagnostics/testsWithJsStdLib/native/inlineClassAsParameterOrReturnType.kt.txt
@@ -8,7 +8,7 @@ public external fun foo(): SomeIC
 public external fun foo(/*0*/ c: SomeIC): SomeIC
 public external fun foo(/*0*/ a: kotlin.Int, /*1*/ c: SomeIC): SomeIC
 public external fun foo(/*0*/ a: kotlin.Int, /*1*/ vararg args: SomeIC /*kotlin.Array<out SomeIC>*/): kotlin.Unit
-public external fun foo(/*0*/ a: kotlin.Int, /*1*/ ui: kotlin.UInt, /*2*/ vararg args: kotlin.UInt /*kotlin.Array<out kotlin.UInt>*/): kotlin.Unit
+public external fun foo(/*0*/ a: kotlin.Int, /*1*/ ui: kotlin.UInt, /*2*/ vararg args: kotlin.UInt /*kotlin.UIntArray*/): kotlin.Unit
 
 public final external class CC {
     public constructor CC(/*0*/ a: SomeIC, /*1*/ b: SomeIC, /*2*/ c: SomeIC)
diff --git a/compiler/testData/multiplatform/incompatibleCallables/output.txt b/compiler/testData/multiplatform/incompatibleCallables/output.txt
index b7ae225d0ab..139cfef8d9e 100644
--- a/compiler/testData/multiplatform/incompatibleCallables/output.txt
+++ b/compiler/testData/multiplatform/incompatibleCallables/output.txt
@@ -1,9 +1,6 @@
 -- Common --
 Exit code: OK
 Output:
-compiler/testData/multiplatform/incompatibleCallables/common.kt:32:19: warning: the feature "coroutines" is experimental (see: https://kotlinlang.org/docs/diagnostics/experimental-coroutines)
-expect fun f21(c: suspend Unit.() -> Unit)
-                  ^
 
 -- JVM --
 Exit code: COMPILATION_ERROR
diff --git a/compiler/tests/org/jetbrains/kotlin/jvm/compiler/CompileKotlinAgainstCustomBinariesTest.kt b/compiler/tests/org/jetbrains/kotlin/jvm/compiler/CompileKotlinAgainstCustomBinariesTest.kt
index 01e1afa8601..e66090e40a9 100644
--- a/compiler/tests/org/jetbrains/kotlin/jvm/compiler/CompileKotlinAgainstCustomBinariesTest.kt
+++ b/compiler/tests/org/jetbrains/kotlin/jvm/compiler/CompileKotlinAgainstCustomBinariesTest.kt
@@ -433,7 +433,7 @@ class CompileKotlinAgainstCustomBinariesTest : AbstractKotlinCompilerIntegration
 
     fun testObsoleteInlineSuspend() {
         val version = intArrayOf(1, 0, 1) // legacy coroutines metadata
-        val options = listOf("-Xcoroutines=enable")
+        val options = listOf("-language-version", "1.2", "-Xcoroutines=enable")
         val library = transformJar(
             compileLibrary("library", additionalOptions = options),
             { _, bytes ->
diff --git a/compiler/tests/org/jetbrains/kotlin/serialization/AbstractVersionRequirementTest.kt b/compiler/tests/org/jetbrains/kotlin/serialization/AbstractVersionRequirementTest.kt
index a4f34af7c32..c6ff006d40f 100644
--- a/compiler/tests/org/jetbrains/kotlin/serialization/AbstractVersionRequirementTest.kt
+++ b/compiler/tests/org/jetbrains/kotlin/serialization/AbstractVersionRequirementTest.kt
@@ -78,6 +78,7 @@ abstract class AbstractVersionRequirementTest : TestCaseWithTmpdir() {
     fun testSuspendFun() {
         doTest(
             VersionRequirement.Version(1, 1), DeprecationLevel.ERROR, null, ProtoBuf.VersionRequirement.VersionKind.LANGUAGE_VERSION, null,
+            customLanguageVersion = LanguageVersion.KOTLIN_1_2,
             fqNames = listOf(
                 "test.topLevel",
                 "test.Foo.member",
@@ -158,6 +159,7 @@ abstract class AbstractVersionRequirementTest : TestCaseWithTmpdir() {
     fun testNestedClassMembers() {
         doTest(
             VersionRequirement.Version(1, 1), DeprecationLevel.ERROR, null, ProtoBuf.VersionRequirement.VersionKind.LANGUAGE_VERSION, null,
+            customLanguageVersion = LanguageVersion.KOTLIN_1_2,
             fqNames = listOf(
                 "test.Outer.Inner.Deep",
                 "test.Outer.Inner.Deep.<init>",