[turbofan] Disable loop peeling for asm.js.

BUG=chromium:669494
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2533303002
Cr-Commit-Position: refs/heads/master@{#41360}

src/compilation-info.h

@@ -49,6 +49,7 @@ class CompilationInfo final {
     kSourcePositionsEnabled = 1 << 13,
     kBailoutOnUninitialized = 1 << 14,
     kOptimizeFromBytecode = 1 << 15,
+    kLoopPeelingEnabled = 1 << 16,
   };
 
   CompilationInfo(ParseInfo* parse_info, Handle<JSFunction> closure);
@@ -172,6 +173,10 @@ class CompilationInfo final {
     return GetFlag(kOptimizeFromBytecode);
   }
 
+  void MarkAsLoopPeelingEnabled() { SetFlag(kLoopPeelingEnabled); }
+
+  bool is_loop_peeling_enabled() const { return GetFlag(kLoopPeelingEnabled); }
+
   bool GeneratePreagedPrologue() const {
     // Generate a pre-aged prologue if we are optimizing for size, which
     // will make code flushing more aggressive. Only apply to Code::FUNCTION,

src/compiler/pipeline.cc

@@ -552,6 +552,9 @@ PipelineCompilationJob::Status PipelineCompilationJob::PrepareJobImpl() {
     if (!FLAG_always_opt) {
       info()->MarkAsBailoutOnUninitialized();
     }
+    if (FLAG_turbo_loop_peeling) {
+      info()->MarkAsLoopPeelingEnabled();
+    }
   }
   if (info()->is_optimizing_from_bytecode() ||
       !info()->shared_info()->asm_function() || FLAG_turbo_asm_deoptimization) {
@@ -1505,7 +1508,7 @@ bool PipelineImpl::CreateGraph() {
     Run<TypedLoweringPhase>();
     RunPrintAndVerify("Lowered typed");
 
-    if (FLAG_turbo_loop_peeling) {
+    if (data->info()->is_loop_peeling_enabled()) {
       Run<LoopPeelingPhase>();
       RunPrintAndVerify("Loops peeled", true);
     } else {