Handle StepIn for constructors through PrepareStep just like for regular calls

src/mips/builtins-mips.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_MIPS
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 358 matching lines @@
 
     // Preserve the incoming parameters on the stack.
     __ AssertUndefinedOrAllocationSite(a2, t0);
     __ SmiTag(a0);
     __ Push(a2, a0, a1, a3);
 
     // 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(isolate);
-      __ li(a2, Operand(debug_step_in_fp));
-      __ lw(a2, MemOperand(a2));
-      __ Branch(&rt_call, ne, a2, Operand(zero_reg));
-
       // Verify that the new target is a JSFunction.
       __ GetObjectType(a3, t1, t0);
       __ Branch(&rt_call, ne, t0, Operand(JS_FUNCTION_TYPE));
 
       // Load the initial map and verify that it is in fact a map.
       // a3: new target
       __ lw(a2, FieldMemOperand(a3, JSFunction::kPrototypeOrInitialMapOffset));
       __ JumpIfSmi(a2, &rt_call);
       __ GetObjectType(a2, t5, t4);
       __ Branch(&rt_call, ne, t4, Operand(MAP_TYPE));
@@ skipping 279 matching lines @@
     __ Branch(&entry);
     __ bind(&loop);
     __ sll(at, t0, kPointerSizeLog2 - 1);
     __ Addu(at, a2, Operand(at));
     __ lw(at, MemOperand(at));
     __ push(at);
     __ bind(&entry);
     __ Subu(t0, t0, Operand(2));
     __ Branch(&loop, ge, t0, 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));
-    __ lw(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
     ParameterCount actual(a0);
     __ InvokeFunction(a1, actual, CALL_FUNCTION, NullCallWrapper());
 
     // Restore context from the frame.
     // v0: result
     // sp[0]: new.target
     // sp[1]: number of arguments (smi-tagged)
@@ skipping 1246 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS