Fix x64 patching of asllocation stub: the pool pointer must be set-up before patching jump is execu…

runtime/vm/assembler_x64.h

 // Copyright (c) 2013, 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_X64_H_
 #define VM_ASSEMBLER_X64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_x64.h directly; use assembler.h instead.
 #endif
@@ skipping 838 matching lines @@
   //   ret PC
   //   .....
   // This code sets this up with the sequence:
   //   pushq rbp
   //   movq rbp, rsp
   //   pushq immediate(0)
   //   .....
   void EnterStubFrame(bool load_pp = false);
   void LeaveStubFrame();
 
+  // Loads pool pointer in 'temp_pp', destroys temp_pc.
+  void SetupPP(Register temp_pp, Register temp_pc);
+
   // Instruction pattern from entrypoint is used in dart frame prologues
   // to set up the frame and save a PC which can be used to figure out the
   // RawInstruction object corresponding to the code running in the frame.
   // entrypoint:
   //   pushq rbp          (size is 1 byte)
   //   movq rbp, rsp      (size is 3 bytes)
   //   call L             (size is 5 bytes)
   //   L:
   static const intptr_t kEntryPointToPcMarkerOffset = 9;
   static intptr_t EntryPointToPcMarkerOffset() {
@@ skipping 257 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_X64_H_