IrBuiltins: refactoring for equality checks

Previously,
* Equals performs IEEE 754 equality check for floating points and
  byte-to-byte checks for other types, including references.
* Ieee754Equals performs IEEE 754 for primitive types
* TotalOrderEquals performs total order equals to all types, including
  floating points.

Now it is simplified,
* Equals performs total order checks for all types.
* Ieee754Equals performs IEEE 754 for primitive types.
* (TotalOrderEquals is removed.)

compiler/backend/src/org/jetbrains/kotlin/codegen/AsmUtil.java

@@ -848,19 +848,30 @@ public class AsmUtil {
         return StackValue.operation(Type.BOOLEAN_TYPE, v -> {
             left.put(AsmTypes.OBJECT_TYPE, left.kotlinType, v);
             right.put(AsmTypes.OBJECT_TYPE, right.kotlinType, v);
-            genAreEqualCall(v);
-
-            if (opToken == KtTokens.EXCLEQ || opToken == KtTokens.EXCLEQEQEQ) {
-                genInvertBoolean(v);
-            }
-            return Unit.INSTANCE;
+            return genAreEqualCall(v, opToken);
         });
     }
 
+    @NotNull
+    public static StackValue genEqualsBoxedOnStack(@NotNull IElementType opToken) {
+        return StackValue.operation(Type.BOOLEAN_TYPE, v -> genAreEqualCall(v, opToken));
+    }
+
     public static void genAreEqualCall(InstructionAdapter v) {
         v.invokestatic(IntrinsicMethods.INTRINSICS_CLASS_NAME, "areEqual", "(Ljava/lang/Object;Ljava/lang/Object;)Z", false);
     }
 
+    @NotNull
+    private static Unit genAreEqualCall(InstructionAdapter v, @NotNull IElementType opToken) {
+        genAreEqualCall(v);
+
+        if (opToken == KtTokens.EXCLEQ || opToken == KtTokens.EXCLEQEQEQ) {
+            genInvertBoolean(v);
+        }
+
+        return Unit.INSTANCE;
+    }
+
     public static void genIEEE754EqualForNullableTypesCall(InstructionAdapter v, Type left, Type right) {
         v.invokestatic(IntrinsicMethods.INTRINSICS_CLASS_NAME, "areEqual", "(" + left.getDescriptor() + right.getDescriptor() + ")Z", false);
     }