MIPS: new classes: no longer experimental.

src/mips64/builtins-mips64.cc

Index: src/mips64/builtins-mips64.cc
diff --git a/src/mips64/builtins-mips64.cc b/src/mips64/builtins-mips64.cc
index 456be8ff7f4710dc9d5cb2f3949245f5acdfae40..2d676a1fa9600e39d80323e793f91a553bab80b4 100644
--- a/src/mips64/builtins-mips64.cc
+++ b/src/mips64/builtins-mips64.cc
@@ -817,10 +817,26 @@ void Builtins::Generate_JSConstructStubForDerived(MacroAssembler* masm) {
     __ Daddu(a4, a4, Operand(-1));
     __ Branch(&loop, ge, a4, Operand(zero_reg));
 
+    __ Daddu(a0, a0, Operand(1));
+
+    // Handle step in.
+    Label skip_step_in;
+    ExternalReference debug_step_in_fp =
+        ExternalReference::debug_step_in_fp_address(masm->isolate());
+    __ li(a2, Operand(debug_step_in_fp));
+    __ ld(a2, MemOperand(a2));
+    __ Branch(&skip_step_in, eq, a2, Operand(zero_reg));
+
+    __ Push(a0, a1, a1);
+    __ CallRuntime(Runtime::kHandleStepInForDerivedConstructors, 1);
+    __ Pop(a0, a1);
+
+    __ bind(&skip_step_in);
+
+
     // Call the function.
     // a0: number of arguments
     // a1: constructor function
-    __ Daddu(a0, a0, Operand(1));
     ParameterCount actual(a0);
     __ InvokeFunction(a1, actual, CALL_FUNCTION, NullCallWrapper());