[JS IR BE] Don't mangle Any::equals method

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

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.ir.backend.js.lower.calls
 
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
+import org.jetbrains.kotlin.ir.backend.js.utils.isEqualsInheritedFromAny
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.IrCall
 import org.jetbrains.kotlin.ir.expressions.IrExpression
@@ -172,10 +173,4 @@ class EqualityAndComparisonCallsTransformer(context: JsIrBackendContext) : Calls
     private fun IrFunction.isMethodOfPotentiallyPrimitiveJSType() =
         isMethodOfPrimitiveJSType() || isFakeOverriddenFromAny()
 
-    private fun IrFunction.isEqualsInheritedFromAny() =
-        name == Name.identifier("equals") &&
-                dispatchReceiverParameter != null &&
-                valueParameters.size == 1 &&
-                valueParameters[0].type.isNullableAny()
-
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/SimpleNameGenerator.kt

@@ -143,6 +143,11 @@ class SimpleNameGenerator : NameGenerator {
             }
             is IrSimpleFunction -> {
 
+                // Handle names for special functions
+                if (declaration.isEqualsInheritedFromAny()) {
+                    return context.staticContext.rootScope.declareName("equals")
+                }
+
                 if (declaration.isStaticMethodOfClass) {
                     nameBuilder.append(getNameForDeclaration(declaration.parent as IrClass, context))
                     nameBuilder.append('.')

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/misc.kt

@@ -6,5 +6,14 @@
 package org.jetbrains.kotlin.ir.backend.js.utils
 
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.types.isNullableAny
+import org.jetbrains.kotlin.name.Name
 
 fun TODO(element: IrElement): Nothing = TODO(element::class.java.simpleName + " is not supported yet here")
+
+fun IrFunction.isEqualsInheritedFromAny() =
+    name == Name.identifier("equals") &&
+            dispatchReceiverParameter != null &&
+            valueParameters.size == 1 &&
+            valueParameters[0].type.isNullableAny()

js/js.translator/testData/box/native/equalsMangling.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // EXPECTED_REACHABLE_NODES: 1290
 data class A(val number: Int)
 

libraries/stdlib/js/irRuntime/core.kt

@@ -14,8 +14,8 @@ fun equals(obj1: dynamic, obj2: dynamic): Boolean {
     }
 
     return js("""
-    if (typeof obj1 === "object" && typeof obj1.equals_kotlin_Any_ === "function") {
+    if (typeof obj1 === "object" && typeof obj1.equals === "function") {
-        return obj1.equals_kotlin_Any_(obj2);
+        return obj1.equals(obj2);
     }
 
     if (obj1 !== obj1) {