[Compiler] Ensure unoptimized code generation is context independent.

Now that Asm.js code is also context independent, move code to ensure context independence
from BytecodeGenerator to FinalizeUnoptimizedCode.

Change-Id: I7738eb3b347ea82764ecd3b5548dc82cb06d2f4e
Reviewed-on: https://chromium-review.googlesource.com/c/1347483Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57730}

src/compiler.cc

@@ -555,8 +555,12 @@ bool FinalizeUnoptimizedCode(
     UnoptimizedCompilationJobList* inner_function_jobs) {
   DCHECK(AllowCompilation::IsAllowed(isolate));
 
-  // TODO(rmcilroy): Clear native context in debug once AsmJS generates doesn't
-  // rely on accessing native context during finalization.
+#ifdef DEBUG
+  // Unoptimized compilation should be context-independent. Verify that we don't
+  // access the native context by nulling it out during finalization.
+  SaveContext save(isolate);
+  isolate->set_context(nullptr);
+#endif
 
   // Allocate scope infos for the literal.
   DeclarationScope::AllocateScopeInfos(parse_info, isolate);

src/interpreter/bytecode-generator.cc

@@ -924,12 +924,6 @@ BytecodeGenerator::BytecodeGenerator(
 Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
     Isolate* isolate, Handle<Script> script) {
   DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
-#ifdef DEBUG
-  // Unoptimized compilation should be context-independent. Verify that we don't
-  // access the native context by nulling it out during finalization.
-  SaveContext save(isolate);
-  isolate->set_context(nullptr);
-#endif
 
   AllocateDeferredConstants(isolate, script);