[turbofan] Add an operator to access the parent frame pointer

src/compiler/arm/code-generator-arm.cc

 // Copyright 2014 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.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/arm/macro-assembler-arm.h"
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
@@ skipping 515 matching lines @@
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
     case kArchStackPointer:
       __ mov(i.OutputRegister(), sp);
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
     case kArchFramePointer:
       __ mov(i.OutputRegister(), fp);
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
+    case kArchParentFramePointer:
+      if (frame_access_state()->frame()->needs_frame()) {
+        __ ldr(i.OutputRegister(), MemOperand(fp, 0));
+      } else {
+        __ mov(i.OutputRegister(), fp);
+      }
+      break;
     case kArchTruncateDoubleToI:
       __ TruncateDoubleToI(i.OutputRegister(), i.InputFloat64Register(0));
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
     case kArchStoreWithWriteBarrier: {
       RecordWriteMode mode =
           static_cast<RecordWriteMode>(MiscField::decode(instr->opcode()));
       Register object = i.InputRegister(0);
       Register value = i.InputRegister(2);
       Register scratch0 = i.TempRegister(0);
@@ skipping 900 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8