[JS IR BE] Fix GetClass on primitive type

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsIrBackendContext.kt

@@ -227,6 +227,12 @@ class JsIrBackendContext(
     val coroutineImplExceptionProperty by lazy { ir.symbols.coroutineImpl.getPropertyDeclaration("exception")!! }
     val coroutineImplExceptionStateProperty by lazy { ir.symbols.coroutineImpl.getPropertyDeclaration("exceptionState")!! }
 
+    val primitiveClassesObject = symbolTable.referenceClass(
+        getClass(FqName.fromSegments(listOf("kotlin", "reflect", "js", "internal", "PrimitiveClasses")))
+    ).owner
+
+    val primitiveClassProperties = primitiveClassesObject.declarations.filterIsInstance<IrProperty>()
+
     private fun referenceOperators() = OperatorNames.ALL.map { name ->
         // TODO to replace KotlinType with IrType we need right equals on IrType
         name to irBuiltIns.primitiveTypes.fold(mutableMapOf<KotlinType, IrFunctionSymbol>()) { m, t ->

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ClassReferenceLowering.kt

@@ -9,26 +9,50 @@ import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.declarations.IrFile
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.expressions.IrClassReference
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrGetClass
-import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.util.defaultType
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
+import org.jetbrains.kotlin.name.Name
 
 class ClassReferenceLowering(val context: JsIrBackendContext) : FileLoweringPass {
     private val intrinsics = context.intrinsics
 
+    private val primitiveClassesObject = context.primitiveClassesObject
+
+    private val primitiveClassProperties = context.primitiveClassProperties
+
+    private val booleanClass = primitiveClassProperties.single { it.name == Name.identifier("booleanClass") }
+    private val intClass = primitiveClassProperties.single { it.name == Name.identifier("intClass") }
+    private val doubleClass = primitiveClassProperties.single { it.name == Name.identifier("doubleClass") }
+
     private fun callGetKClassFromExpression(returnType: IrType, typeArgument: IrType, argument: IrExpression) =
         JsIrBuilder.buildCall(intrinsics.jsGetKClassFromExpression, returnType, listOf(typeArgument)).apply {
             putValueArgument(0, argument)
         }
 
-    private fun callGetKClass(returnType: IrType, typeArgument: IrType, argument: IrExpression) =
-        JsIrBuilder.buildCall(intrinsics.jsGetKClass, returnType, listOf(typeArgument)).apply {
-            putValueArgument(0, argument)
+
+    private fun getPrimitiveClass(target: IrSimpleFunction, returnType: IrType) =
+        JsIrBuilder.buildCall(target.symbol, returnType).apply {
+            dispatchReceiver = JsIrBuilder.buildGetObjectValue(primitiveClassesObject.defaultType, primitiveClassesObject.symbol)
         }
 
+    private fun callGetKClass(returnType: IrType, typeArgument: IrType) = when {
+        typeArgument.isBoolean() -> getPrimitiveClass(booleanClass.getter!!, returnType)
+        typeArgument.isByte() -> getPrimitiveClass(intClass.getter!!, returnType)
+        typeArgument.isShort() -> getPrimitiveClass(intClass.getter!!, returnType)
+        typeArgument.isInt() -> getPrimitiveClass(intClass.getter!!, returnType)
+        typeArgument.isFloat() -> getPrimitiveClass(doubleClass.getter!!, returnType)
+        typeArgument.isDouble() -> getPrimitiveClass(doubleClass.getter!!, returnType)
+        else -> JsIrBuilder.buildCall(intrinsics.jsGetKClass, returnType, listOf(typeArgument)).apply {
+            putValueArgument(0, callJsClass(typeArgument))
+        }
+    }
+
     private fun callJsClass(type: IrType) =
         JsIrBuilder.buildCall(intrinsics.jsClass, typeArguments = listOf(type))
 
@@ -44,8 +68,7 @@ class ClassReferenceLowering(val context: JsIrBackendContext) : FileLoweringPass
             override fun visitClassReference(expression: IrClassReference) =
                 callGetKClass(
                     returnType = expression.type,
-                    typeArgument = expression.classType,
-                    argument = callJsClass(expression.classType)
+                    typeArgument = expression.classType
                 )
         })
     }

compiler/testData/codegen/box/classLiteral/bound/primitives.kt

@@ -1,5 +1,3 @@
-// IGNORE_BACKEND: JS_IR
-
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals