Add 'suspendWithCurrentContinuation' and 'Suspend' object in built-ins

They are part of the new suspension convention, relevant
support in backends will be added in later commits

 #KT-14924 In Progress

compiler/testData/builtin-classes/default/kotlin-coroutines.txt

@@ -0,0 +1,16 @@
+package-fragment kotlin.coroutines
+
+@kotlin.SinceKotlin(version = "1.1") public inline suspend fun </*0*/ T> suspendWithCurrentContinuation(/*0*/ body: (kotlin.coroutines.Continuation<T>) -> kotlin.Any?): T
+
+@kotlin.SinceKotlin(version = "1.1") @kotlin.annotation.Target(allowedTargets = {AnnotationTarget.CLASS}) @kotlin.annotation.Retention(value = AnnotationRetention.BINARY) public final annotation class AllowSuspendExtensions : kotlin.Annotation {
+    /*primary*/ public constructor AllowSuspendExtensions()
+}
+
+@kotlin.SinceKotlin(version = "1.1") public interface Continuation</*0*/ in P> {
+    public abstract fun resume(/*0*/ data: P): kotlin.Unit
+    public abstract fun resumeWithException(/*0*/ exception: kotlin.Throwable): kotlin.Unit
+}
+
+@kotlin.SinceKotlin(version = "1.1") public object Suspend {
+    /*primary*/ private constructor Suspend()
+}

compiler/testData/diagnostics/tests/coroutines/suspendWithCurrentContinuation.kt

@@ -0,0 +1,31 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !CHECK_TYPE
+class Controller {
+    suspend fun noParams(): Unit = suspendWithCurrentContinuation {
+        if (hashCode() % 2 == 0) {
+            it.resume(Unit)
+            Suspend
+        }
+        else {
+            Unit
+        }
+    }
+    suspend fun yieldString(value: String) = suspendWithCurrentContinuation<Int> {
+        it.resume(1)
+        it checkType { _<Continuation<Int>>() }
+        it.resume(<!TYPE_MISMATCH!>""<!>)
+
+        // We can return anything here, 'suspendWithCurrentContinuation' is not very type-safe
+        // Also we can call resume and then return the value too, but it's still just our problem
+        "Not-int"
+    }
+}
+
+fun builder(coroutine c: Controller.() -> Continuation<Unit>) {}
+
+fun test() {
+    builder {
+        noParams() checkType { _<Unit>() }
+        yieldString("abc") checkType { _<Int>() }
+    }
+}

compiler/testData/diagnostics/tests/coroutines/suspendWithCurrentContinuation.txt

@@ -0,0 +1,13 @@
+package
+
+public fun builder(/*0*/ coroutine c: Controller.() -> kotlin.coroutines.Continuation<kotlin.Unit>): kotlin.Unit
+public fun test(): kotlin.Unit
+
+public final class Controller {
+    public constructor Controller()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final suspend fun noParams(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    public final suspend fun yieldString(/*0*/ value: kotlin.String): kotlin.Int
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -4300,6 +4300,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("suspendWithCurrentContinuation.kt")
+            public void testSuspendWithCurrentContinuation() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/coroutines/suspendWithCurrentContinuation.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("tryCatchLambda.kt")
             public void testTryCatchLambda() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/coroutines/tryCatchLambda.kt");

compiler/tests/org/jetbrains/kotlin/serialization/builtins/LoadBuiltinsTest.java

@@ -91,7 +91,7 @@ public class LoadBuiltinsTest extends KotlinTestWithEnvironment {
         ModuleDescriptor module =
                 LazyResolveTestUtilsKt.createResolveSessionForFiles(getEnvironment().getProject(), files, false).getModuleDescriptor();
 
-        for (FqName packageFqName : CollectionsKt.listOf(BUILT_INS_PACKAGE_FQ_NAME, COLLECTIONS_PACKAGE_FQ_NAME, RANGES_PACKAGE_FQ_NAME)) {
+        for (FqName packageFqName : CollectionsKt.listOf(BUILT_INS_PACKAGE_FQ_NAME, COLLECTIONS_PACKAGE_FQ_NAME, RANGES_PACKAGE_FQ_NAME, COROUTINES_PACKAGE_FQ_NAME)) {
             PackageFragmentDescriptor fromLazyResolve =
                     CollectionsKt.single(module.getPackage(packageFqName).getFragments());
             if (fromLazyResolve instanceof LazyPackageDescriptor) {