KT-37059 Support 'String?.plus(Any?)' in JVM_IR

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/intrinsics/IrIntrinsicMethods.kt

@@ -91,6 +91,12 @@ class IrIntrinsicMethods(val irBuiltIns: IrBuiltIns, val symbols: JvmSymbols) {
                     "enumValueOf",
                     listOf(KotlinBuiltIns.FQ_NAMES.string.toSafe())
                 ) to EnumValueOf,
+                Key(
+                    KotlinBuiltIns.BUILT_INS_PACKAGE_FQ_NAME,
+                    KotlinBuiltIns.FQ_NAMES.string.toSafe(),
+                    "plus",
+                    listOf(KotlinBuiltIns.FQ_NAMES.any.toSafe())
+                ) to StringPlus,
                 irBuiltIns.eqeqSymbol.toKey()!! to Equals(KtTokens.EQEQ),
                 irBuiltIns.eqeqeqSymbol.toKey()!! to Equals(KtTokens.EQEQEQ),
                 irBuiltIns.ieee754equalsFunByOperandType[irBuiltIns.floatClass]!!.toKey()!! to Ieee754Equals(Type.FLOAT_TYPE),

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/intrinsics/StringPlus.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.jvm.intrinsics
+
+import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
+import org.jetbrains.kotlin.codegen.intrinsics.IntrinsicMethods
+import org.jetbrains.kotlin.ir.expressions.IrFunctionAccessExpression
+import org.jetbrains.kotlin.resolve.jvm.AsmTypes
+import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodSignature
+import org.jetbrains.org.objectweb.asm.Type
+
+object StringPlus : IntrinsicMethod() {
+
+    override fun toCallable(
+        expression: IrFunctionAccessExpression,
+        signature: JvmMethodSignature,
+        context: JvmBackendContext
+    ): IrIntrinsicFunction =
+        IrIntrinsicFunction.create(expression, signature, context, listOf(AsmTypes.JAVA_STRING_TYPE, AsmTypes.OBJECT_TYPE)) {
+            it.invokestatic(
+                IntrinsicMethods.INTRINSICS_CLASS_NAME,
+                "stringPlus",
+                Type.getMethodDescriptor(AsmTypes.JAVA_STRING_TYPE, AsmTypes.JAVA_STRING_TYPE, AsmTypes.OBJECT_TYPE),
+                false
+            )
+        }
+}