[Compile] Remove unused language mode from DeclareGlobalsFlag.

BUG=v8:5203

Change-Id: Id7f1b3a50f5f407e9fdada8a5b62a7ada8d966df
Reviewed-on: https://chromium-review.googlesource.com/593951Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47015}

src/compilation-info.cc

@@ -190,10 +190,8 @@ StackFrame::Type CompilationInfo::GetOutputStackFrameType() const {
 }
 
 int CompilationInfo::GetDeclareGlobalsFlags() const {
-  DCHECK(DeclareGlobalsLanguageMode::is_valid(parse_info()->language_mode()));
   return DeclareGlobalsEvalFlag::encode(parse_info()->is_eval()) |
-         DeclareGlobalsNativeFlag::encode(parse_info()->is_native()) |
-         DeclareGlobalsLanguageMode::encode(parse_info()->language_mode());
+         DeclareGlobalsNativeFlag::encode(parse_info()->is_native());
 }
 
 SourcePositionTableBuilder::RecordingMode

src/runtime/runtime.h

@@ -825,8 +825,6 @@ class AllocateTargetSpace : public BitField<AllocationSpace, 1, 3> {};
 
 class DeclareGlobalsEvalFlag : public BitField<bool, 0, 1> {};
 class DeclareGlobalsNativeFlag : public BitField<bool, 1, 1> {};
-STATIC_ASSERT(LANGUAGE_END == 2);
-class DeclareGlobalsLanguageMode : public BitField<LanguageMode, 2, 1> {};
 
 // A set of bits returned by Runtime_GetOptimizationStatus.
 // These bits must be in sync with bits defined in test/mjsunit/mjsunit.js