Remove now-unused kIllegalBytecode bailout reason.

src/bailout-reason.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_BAILOUT_REASON_H_
 #define V8_BAILOUT_REASON_H_
 
 namespace v8 {
 namespace internal {
 
@@ skipping 73 matching lines @@
   V(kFunctionCallsEval, "Function calls eval")                                 \
   V(kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,                      \
     "The function_data field should be a BytecodeArray on interpreter entry")  \
   V(kGeneratedCodeIsTooLarge, "Generated code is too large")                   \
   V(kGenerator, "Generator")                                                   \
   V(kGlobalFunctionsMustHaveInitialMap,                                        \
     "Global functions must have initial map")                                  \
   V(kGraphBuildingFailed, "Optimized graph construction failed")               \
   V(kHeapNumberMapRegisterClobbered, "HeapNumberMap register clobbered")       \
   V(kHydrogenFilter, "Optimization disabled by filter")                        \
-  V(kIllegalBytecode, "Illegal bytecode")                                      \
   V(kImportDeclaration, "Import declaration")                                  \
   V(kIndexIsNegative, "Index is negative")                                     \
   V(kIndexIsTooLarge, "Index is too large")                                    \
   V(kInliningBailedOut, "Inlining bailed out")                                 \
   V(kInputGPRIsExpectedToHaveUpper32Cleared,                                   \
     "Input GPR is expected to have upper32 cleared")                           \
   V(kInputStringTooLong, "Input string too long")                              \
   V(kInteger32ToSmiFieldWritingToNonSmiLocation,                               \
     "Integer32ToSmiField writing to non-smi location")                         \
   V(kInvalidBytecode, "Invalid bytecode")                                      \
@@ skipping 183 matching lines @@
 };
 #undef ERROR_MESSAGES_CONSTANTS
 
 
 const char* GetBailoutReason(BailoutReason reason);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_BAILOUT_REASON_H_