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

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index 99beda4eee8cba1c5106e0e4694a6c766bd0482f..3cfae67f44fbb3090520fb5571be7cd3727c2c0d 100644
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -2052,8 +2052,13 @@ class LCallRuntime V8_FINAL : public LTemplateInstruction<1, 1, 0> {
   DECLARE_CONCRETE_INSTRUCTION(CallRuntime, "call-runtime")
   DECLARE_HYDROGEN_ACCESSOR(CallRuntime)
 
+  virtual bool ClobbersDoubleRegisters() const V8_OVERRIDE {
+    return save_doubles() == kDontSaveFPRegs;
+  }
+
   const Runtime::Function* function() const { return hydrogen()->function(); }
   int arity() const { return hydrogen()->argument_count(); }
+  SaveFPRegsMode save_doubles() const { return hydrogen()->save_doubles(); }
 };