Introduce LanguageMode, drop StrictMode.

src/arm/lithium-arm.h

Index: src/arm/lithium-arm.h
diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index b62af52a64b62de7a8dda556f69152904328a559..fc8b300f3550949a673924dfc442a9fa666544cf 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -2231,7 +2231,7 @@ class LStoreNamedGeneric FINAL : public LTemplateInstruction<0, 3, 0> {
   void PrintDataTo(StringStream* stream) OVERRIDE;
 
   Handle<Object> name() const { return hydrogen()->name(); }
-  StrictMode strict_mode() { return hydrogen()->strict_mode(); }
+  LanguageMode language_mode() { return hydrogen()->language_mode(); }
 };
 
 
@@ -2294,7 +2294,7 @@ class LStoreKeyedGeneric FINAL : public LTemplateInstruction<0, 4, 0> {
 
   void PrintDataTo(StringStream* stream) OVERRIDE;
 
-  StrictMode strict_mode() { return hydrogen()->strict_mode(); }
+  LanguageMode language_mode() { return hydrogen()->language_mode(); }
 };