ARM64: Preserve x8 and x9 when necessary.

src/arm64/macro-assembler-arm64.cc

Index: src/arm64/macro-assembler-arm64.cc
diff --git a/src/arm64/macro-assembler-arm64.cc b/src/arm64/macro-assembler-arm64.cc
index 97361f52484f7d61a15374c6f037272b573f15ed..70d601b2e6e0399fe4ceabb0ae11ef1e6a094be3 100644
--- a/src/arm64/macro-assembler-arm64.cc
+++ b/src/arm64/macro-assembler-arm64.cc
@@ -53,7 +53,9 @@ MacroAssembler::MacroAssembler(Isolate* arg_isolate,
 #endif
       has_frame_(false),
       use_real_aborts_(true),
-      sp_(jssp), tmp_list_(ip0, ip1), fptmp_list_(fp_scratch1, fp_scratch2) {
+      sp_(jssp),
+      tmp_list_(DefaultTmpList()),
+      fptmp_list_(DefaultFPTmpList()) {
   if (isolate() != NULL) {
     code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
                                   isolate());
@@ -61,6 +63,16 @@ MacroAssembler::MacroAssembler(Isolate* arg_isolate,
 }
 
 
+CPURegList MacroAssembler::DefaultTmpList() {
+  return CPURegList(ip0, ip1);
+}
+
+
+CPURegList MacroAssembler::DefaultFPTmpList() {
+  return CPURegList(fp_scratch1, fp_scratch2);
+}
+
+
 void MacroAssembler::LogicalMacro(const Register& rd,
                                   const Register& rn,
                                   const Operand& operand,
@@ -4729,8 +4741,7 @@ void MacroAssembler::Abort(BailoutReason reason) {
   // We need some scratch registers for the MacroAssembler, so make sure we have
   // some. This is safe here because Abort never returns.
   RegList old_tmp_list = TmpList()->list();
-  TmpList()->Combine(ip0);
-  TmpList()->Combine(ip1);
+  TmpList()->Combine(MacroAssembler::DefaultTmpList());
 
   if (use_real_aborts()) {
     // Avoid infinite recursion; Push contains some assertions that use Abort.