AbortOptimization, RetryOptimization preserve first bailout reason

The current logic appears to have been introduced in
https://codereview.chromium.org/596783002.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/836033005

Cr-Commit-Position: refs/heads/master@{#26043}

src/bailout-reason.h

@@ -301,7 +301,6 @@ namespace internal {
     "Unexpected unused properties of string wrapper")                          \
   V(kUnimplemented, "unimplemented")                                           \
   V(kUninitializedKSmiConstantRegister, "Uninitialized kSmiConstantRegister")  \
-  V(kUnknown, "Unknown")                                                       \
   V(kUnsupportedConstCompoundAssignment,                                       \
     "Unsupported const compound assignment")                                   \
   V(kUnsupportedCountOperationWithConst,                                       \

src/compiler.cc

@@ -185,7 +185,7 @@ void CompilationInfo::Initialize(Isolate* isolate,
     DCHECK(strict_mode() == SLOPPY);
     SetStrictMode(shared_info_->strict_mode());
   }
-  bailout_reason_ = kUnknown;
+  bailout_reason_ = kNoReason;
 
   if (!shared_info().is_null() && shared_info()->is_compiled()) {
     // We should initialize the CompilationInfo feedback vector from the

src/compiler.h

@@ -330,12 +330,15 @@ class CompilationInfo {
   }
 
   void AbortOptimization(BailoutReason reason) {
-    if (bailout_reason_ != kNoReason) bailout_reason_ = reason;
+    DCHECK(reason != kNoReason);
+    if (bailout_reason_ == kNoReason) bailout_reason_ = reason;
     SetFlag(kDisableFutureOptimization);
   }
 
   void RetryOptimization(BailoutReason reason) {
-    if (bailout_reason_ != kNoReason) bailout_reason_ = reason;
+    DCHECK(reason != kNoReason);
+    if (GetFlag(kDisableFutureOptimization)) return;
+    bailout_reason_ = reason;
   }
 
   BailoutReason bailout_reason() const { return bailout_reason_; }