Fixed crashes exposed though fuzzing.

src/ia32/macro-assembler-ia32.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 565 matching lines @@
 
   // Unlink the stack handler on top of the stack from the try handler chain.
   void PopTryHandler();
 
   // Throw to the top handler in the try hander chain.
   void Throw(Register value);
 
   // Throw past all JS frames to the top JS entry frame.
   void ThrowUncatchable(Register value);
 
+  // Throw a message string as an exception.
+  void Throw(BailoutReason reason);
+
+  // Throw a message string as an exception if a condition is not true.
+  void ThrowIfNot(Condition cc, BailoutReason reason);
+
   // ---------------------------------------------------------------------------
   // Inline caching support
 
   // Generate code for checking access rights - used for security checks
   // on access to global objects across environments. The holder register
   // is left untouched, but the scratch register is clobbered.
   void CheckAccessGlobalProxy(Register holder_reg,
                               Register scratch1,
                               Register scratch2,
                               Label* miss);
@@ skipping 338 matching lines @@
 
   // Checks if the given register or operand is a unique name
   void JumpIfNotUniqueName(Register reg, Label* not_unique_name,
                            Label::Distance distance = Label::kFar) {
     JumpIfNotUniqueName(Operand(reg), not_unique_name, distance);
   }
 
   void JumpIfNotUniqueName(Operand operand, Label* not_unique_name,
                            Label::Distance distance = Label::kFar);
 
+  void EmitSeqStringSetCharCheck(Register string,
+                                 Register index,
+                                 Register value,
+                                 uint32_t encoding_mask);
+
   static int SafepointRegisterStackIndex(Register reg) {
     return SafepointRegisterStackIndex(reg.code());
   }
 
   // Activation support.
   void EnterFrame(StackFrame::Type type);
   void LeaveFrame(StackFrame::Type type);
 
   // Expects object in eax and returns map with validated enum cache
   // in eax.  Assumes that any other register can be used as a scratch.
@@ skipping 162 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_MACRO_ASSEMBLER_IA32_H_