Implement CFI for Optimizing.

CFI is necessary for stack unwinding in gdb, lldb, and libunwind.

Change-Id: I1a3480e3a4a99f48bf7e6e63c4e83a80cfee40a2
diff --git a/compiler/optimizing/code_generator_arm64.h b/compiler/optimizing/code_generator_arm64.h
index 7edb129..9430e31 100644
--- a/compiler/optimizing/code_generator_arm64.h
+++ b/compiler/optimizing/code_generator_arm64.h
@@ -227,6 +227,8 @@
 
   void GenerateFrameEntry() OVERRIDE;
   void GenerateFrameExit() OVERRIDE;
+  void SpillRegisters(vixl::CPURegList registers, int offset);
+  void UnspillRegisters(vixl::CPURegList registers, int offset);
 
   vixl::CPURegList GetFramePreservedCoreRegisters() const {
     return vixl::CPURegList(vixl::CPURegister::kRegister, vixl::kXRegSize,