Lazily save double registers for HCallRuntime instructions within Hydrogen code stubs.

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
diff --git a/src/arm/macro-assembler-arm.h b/src/arm/macro-assembler-arm.h
index 6d08ab9bd1686b98e5d41a48a626b79d9a02aa61..381ed8cf0f82c4163a9d7d2999866bf89b7c7970 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -1044,11 +1044,18 @@ class MacroAssembler: public Assembler {
   void TailCallStub(CodeStub* stub, Condition cond = al);
 
   // Call a runtime routine.
-  void CallRuntime(const Runtime::Function* f, int num_arguments);
-  void CallRuntimeSaveDoubles(Runtime::FunctionId id);
+  void CallRuntime(const Runtime::Function* f,
+                   int num_arguments,
+                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+  void CallRuntimeSaveDoubles(Runtime::FunctionId id) {
+    const Runtime::Function* function = Runtime::FunctionForId(id);
+    CallRuntime(function, function->nargs, kSaveFPRegs);
+  }
 
   // Convenience function: Same as above, but takes the fid instead.
-  void CallRuntime(Runtime::FunctionId fid, int num_arguments);
+  void CallRuntime(Runtime::FunctionId id, int num_arguments) {
+    CallRuntime(Runtime::FunctionForId(id), num_arguments);
+  }
 
   // Convenience function: call an external reference.
   void CallExternalReference(const ExternalReference& ext,