Do not optimize == for KClasses in redundant boxing elimination

For primitive wrappers such as java.lang.Integer,
  jlc = java.lang.Integer.class
  jlt = java.lang.Integer.TYPE
  !(ljc.equals(ljt))
However, in Kotlin corresponding KClass instances are equal.

 #KT-17748 Fixed Target versions 1.1.50
 #KT-17879 Fixed Target versions 1.1.50

compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.kt

@@ -233,11 +233,10 @@ fun AbstractInsnNode.isAreEqualIntrinsic() =
             desc == "(Ljava/lang/Object;Ljava/lang/Object;)Z"
         }
 
+private val shouldUseEqualsForWrappers = setOf(Type.DOUBLE_TYPE, Type.FLOAT_TYPE, AsmTypes.JAVA_CLASS_TYPE)
+
 fun canValuesBeUnboxedForAreEqual(values: List<BasicValue>): Boolean =
-        !values.any {
+        values.none { getUnboxedType(it.type) in shouldUseEqualsForWrappers }
-            val unboxedType = getUnboxedType(it.type)
-            unboxedType == Type.DOUBLE_TYPE || unboxedType == Type.FLOAT_TYPE
-        }
 
 fun AbstractInsnNode.isJavaLangComparableCompareToForSameTypedBoxedValues(values: List<BasicValue>) =
         isJavaLangComparableCompareTo() && areSameTypedBoxedValues(values)

compiler/testData/codegen/box/boxingOptimization/kClassEquals.kt

@@ -0,0 +1,20 @@
+// IGNORE_BACKEND: JS, NATIVE
+
+fun test(a: Any) = when (a::class) {
+    String::class -> "String"
+    Int::class -> "Int"
+    Boolean::class -> "Boolean"
+    else -> "Else"
+}
+
+fun box(): String {
+    val s = ""
+    val i = 0
+    val b = false
+
+    if (test(s) != "String") return "Fail 1"
+    if (test(i) != "Int") return "Fail 2"
+    if (test(b) != "Boolean") return "Fail 3"
+
+    return "OK"
+}

compiler/testData/codegen/box/boxingOptimization/kt17748.kt

@@ -0,0 +1,17 @@
+// IGNORE_BACKEND: JS, NATIVE
+
+fun box(): String {
+    42.doSwitchInt()
+    "".doSwitchString()
+    return "OK"
+}
+
+inline fun <reified E> E.doSwitchInt(): String = when (E::class) {
+    Int::class -> "success!"
+    else -> throw AssertionError()
+}
+
+inline fun <reified E> E.doSwitchString(): String = when(E::class) {
+    String::class -> "success!"
+    else -> throw AssertionError()
+}

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -950,12 +950,24 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             doTest(fileName);
         }
 
+        @TestMetadata("kClassEquals.kt")
+        public void testKClassEquals() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kClassEquals.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt15871.kt")
         public void testKt15871() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt15871.kt");
             doTest(fileName);
         }
 
+        @TestMetadata("kt17748.kt")
+        public void testKt17748() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt17748.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt19767.kt")
         public void testKt19767() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt19767.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -950,12 +950,24 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kClassEquals.kt")
+        public void testKClassEquals() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kClassEquals.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt15871.kt")
         public void testKt15871() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt15871.kt");
             doTest(fileName);
         }
 
+        @TestMetadata("kt17748.kt")
+        public void testKt17748() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt17748.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt19767.kt")
         public void testKt19767() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt19767.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -950,12 +950,24 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             doTest(fileName);
         }
 
+        @TestMetadata("kClassEquals.kt")
+        public void testKClassEquals() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kClassEquals.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt15871.kt")
         public void testKt15871() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt15871.kt");
             doTest(fileName);
         }
 
+        @TestMetadata("kt17748.kt")
+        public void testKt17748() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt17748.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt19767.kt")
         public void testKt19767() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt19767.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -1148,12 +1148,36 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kClassEquals.kt")
+        public void testKClassEquals() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kClassEquals.kt");
+            try {
+                doTest(fileName);
+            }
+            catch (Throwable ignore) {
+                return;
+            }
+            throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
+        }
+
         @TestMetadata("kt15871.kt")
         public void testKt15871() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt15871.kt");
             doTest(fileName);
         }
 
+        @TestMetadata("kt17748.kt")
+        public void testKt17748() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt17748.kt");
+            try {
+                doTest(fileName);
+            }
+            catch (Throwable ignore) {
+                return;
+            }
+            throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
+        }
+
         @TestMetadata("kt19767.kt")
         public void testKt19767() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/boxingOptimization/kt19767.kt");