Introduce LanguageMode, drop StrictMode.

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 854e5edfb1a98e1b20d7f4166c08d864cc141275..e22b8735731d8a2306a557e979bedfec5730d171 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -140,8 +140,7 @@ bool LCodeGen::GeneratePrologue() {
     // Sloppy mode functions and builtins need to replace the receiver with the
     // global proxy when called as functions (without an explicit receiver
     // object).
-    if (info_->this_has_uses() &&
-        info_->strict_mode() == SLOPPY &&
+    if (info_->this_has_uses() && is_sloppy(info_->language_mode()) &&
         !info_->is_native()) {
       Label ok;
       // +1 for return address.
@@ -4174,7 +4173,7 @@ void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
   DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
 
   __ mov(StoreDescriptor::NameRegister(), instr->name());
-  Handle<Code> ic = StoreIC::initialize_stub(isolate(), instr->strict_mode());
+  Handle<Code> ic = StoreIC::initialize_stub(isolate(), instr->language_mode());
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 }
 
@@ -4352,7 +4351,7 @@ void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
   DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
 
   Handle<Code> ic =
-      CodeFactory::KeyedStoreIC(isolate(), instr->strict_mode()).code();
+      CodeFactory::KeyedStoreIC(isolate(), instr->language_mode()).code();
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 }
 
@@ -5369,7 +5368,7 @@ void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
   // space for nested functions that don't need literals cloning.
   bool pretenure = instr->hydrogen()->pretenure();
   if (!pretenure && instr->hydrogen()->has_no_literals()) {
-    FastNewClosureStub stub(isolate(), instr->hydrogen()->strict_mode(),
+    FastNewClosureStub stub(isolate(), instr->hydrogen()->language_mode(),
                             instr->hydrogen()->kind());
     __ mov(ebx, Immediate(instr->hydrogen()->shared_info()));
     CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);