Handle StepIn for constructors through PrepareStep just like for regular calls

src/x64/builtins-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 125 matching lines @@
     __ Push(rbx);
     __ Integer32ToSmi(rax, rax);
     __ Push(rax);
     __ Push(rdi);
     __ Push(rdx);
 
     // Try to allocate the object without transitioning into C code. If any of
     // 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(masm->isolate());
-      __ Move(kScratchRegister, debug_step_in_fp);
-      __ cmpp(Operand(kScratchRegister, 0), Immediate(0));
-      __ j(not_equal, &rt_call);
-
       // Verify that the new target is a JSFunction.
       __ CmpObjectType(rdx, JS_FUNCTION_TYPE, rbx);
       __ j(not_equal, &rt_call);
 
       // Load the initial map and verify that it is in fact a map.
       // rdx: new target
       __ movp(rax, FieldOperand(rdx, JSFunction::kPrototypeOrInitialMapOffset));
       // Will both indicate a NULL and a Smi
       DCHECK(kSmiTag == 0);
       __ JumpIfSmi(rax, &rt_call);
@@ skipping 257 matching lines @@
     // Copy arguments and receiver to the expression stack.
     Label loop, entry;
     __ movp(rcx, rax);
     __ jmp(&entry);
     __ bind(&loop);
     __ Push(Operand(rbx, rcx, times_pointer_size, 0));
     __ bind(&entry);
     __ decp(rcx);
     __ j(greater_equal, &loop);
 
-    // Handle step in.
-    Label skip_step_in;
-    ExternalReference debug_step_in_fp =
-        ExternalReference::debug_step_in_fp_address(masm->isolate());
-    __ Move(kScratchRegister, debug_step_in_fp);
-    __ cmpp(Operand(kScratchRegister, 0), Immediate(0));
-    __ j(equal, &skip_step_in);
-
-    __ Push(rax);
-    __ Push(rdi);
-    __ Push(rdi);
-    __ CallRuntime(Runtime::kHandleStepInForDerivedConstructors, 1);
-    __ Pop(rdi);
-    __ Pop(rax);
-
-    __ bind(&skip_step_in);
-
     // Call the function.
     ParameterCount actual(rax);
     __ InvokeFunction(rdi, actual, CALL_FUNCTION, NullCallWrapper());
 
     // Restore context from the frame.
     __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
 
     // Get arguments count, skipping over new.target.
     __ movp(rbx, Operand(rsp, kPointerSize));  // Get arguments count.
   }                                            // Leave construct frame.
@@ skipping 1545 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64