A64: Add support for floating-point registers in PushSafepointRegistersScope.

src/a64/macro-assembler-a64.h

Index: src/a64/macro-assembler-a64.h
diff --git a/src/a64/macro-assembler-a64.h b/src/a64/macro-assembler-a64.h
index e09f4375d5d4ae5e73da23a551fdb6794a2b84af..3635c831ff4874c220bcae0fd341795225fe06b4 100644
--- a/src/a64/macro-assembler-a64.h
+++ b/src/a64/macro-assembler-a64.h
@@ -1574,6 +1574,9 @@ class MacroAssembler : public Assembler {
   void PushSafepointRegisters();
   void PopSafepointRegisters();
 
+  void PushSafepointFPRegisters();
+  void PopSafepointFPRegisters();
+
   // Store value in register src in the safepoint stack slot for register dst.
   void StoreToSafepointRegisterSlot(Register src, Register dst) {
     Poke(src, SafepointRegisterStackIndex(dst.code()) * kPointerSize);