Handle StepIn for constructors through PrepareStep just like for regular calls

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 c60be85e3646370fc3043c966a13cac7033858ff..6d719081a4103b4d807b4afaf804f23271e140ca 100644
--- a/src/mips64/builtins-mips64.cc
+++ b/src/mips64/builtins-mips64.cc
@@ -373,12 +373,6 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     // the preconditions is not met, the code bails out to the runtime call.
     Label rt_call, allocated;
     if (FLAG_inline_new) {
-      ExternalReference debug_step_in_fp =
-          ExternalReference::debug_step_in_fp_address(isolate);
-      __ li(a2, Operand(debug_step_in_fp));
-      __ ld(a2, MemOperand(a2));
-      __ Branch(&rt_call, ne, a2, Operand(zero_reg));
-
       // Verify that the new target is a JSFunction.
       __ GetObjectType(a3, a5, a4);
       __ Branch(&rt_call, ne, a4, Operand(JS_FUNCTION_TYPE));
@@ -679,21 +673,6 @@ void Builtins::Generate_JSConstructStubForDerived(MacroAssembler* masm) {
     __ Daddu(a4, a4, Operand(-1));
     __ Branch(&loop, ge, a4, Operand(zero_reg));
 
-    // 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