Bump the C stack pointer when building Dart frames to maintain the ARM64 ABI requirements without g…

runtime/vm/assembler_arm64.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_ARM64_H_
 #define VM_ASSEMBLER_ARM64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm64.h directly; use assembler.h instead.
 #endif
@@ skipping 1331 matching lines @@
                     Register scratch,
                     Label* miss);
 
   void UpdateRangeFeedback(Register value,
                            intptr_t idx,
                            Register ic_data,
                            Register scratch1,
                            Register scratch2,
                            Label* miss);
 
+  void SetupDartSP();
+  void RestoreCSP();
+
   void EnterFrame(intptr_t frame_size);
   void LeaveFrame();
 
-  // When entering Dart code from C++, we copy the system stack pointer (CSP)
-  // to the Dart stack pointer (SP), and reserve a little space for the stack
-  // to grow.
-  void SetupDartSP(intptr_t reserved_space) {
-    ASSERT(Utils::IsAligned(reserved_space, 16));
-    mov(SP, CSP);
-    sub(CSP, CSP, Operand(reserved_space));
-  }
-
   void CheckCodePointer();
   void RestoreCodePointer();
 
   void EnterDartFrame(intptr_t frame_size, Register new_pp = kNoRegister);
   void EnterOsrFrame(intptr_t extra_size, Register new_pp);
   void LeaveDartFrame(RestorePP restore_pp = kRestoreCallerPP);
 
   void EnterCallRuntimeFrame(intptr_t frame_size);
   void LeaveCallRuntimeFrame();
   void CallRuntime(const RuntimeEntry& entry, intptr_t argument_count);
@@ skipping 590 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM64_H_