ARM64: Remove suspend register.

It also clean up build/remove frame used by JNI compiler and generates
stp/ldp instead of str/ldr. Also x19 has been unblocked in both quick and
optimizing compiler.

Change-Id: Idbeac0942265f493266b2ef9b7a65bb4054f0e2d
diff --git a/compiler/utils/arm64/assembler_arm64.h b/compiler/utils/arm64/assembler_arm64.h
index 8973b9c..b7715af 100644
--- a/compiler/utils/arm64/assembler_arm64.h
+++ b/compiler/utils/arm64/assembler_arm64.h
@@ -83,6 +83,9 @@
   // Copy instructions out of assembly buffer into the given region of memory.
   void FinalizeInstructions(const MemoryRegion& region);
 
+  void SpillRegisters(vixl::CPURegList registers, int offset);
+  void UnspillRegisters(vixl::CPURegList registers, int offset);
+
   // Emit code that will create an activation on the stack.
   void BuildFrame(size_t frame_size, ManagedRegister method_reg,
                   const std::vector<ManagedRegister>& callee_save_regs,