Fixed crashes exposed though fuzzing.

src/ia32/macro-assembler-ia32.h

Index: src/ia32/macro-assembler-ia32.h
diff --git a/src/ia32/macro-assembler-ia32.h b/src/ia32/macro-assembler-ia32.h
index 29bb78d1b80b4112bf31d9dafbb99b66b4ccba01..1bdf855ce38f956e9cdd504b27a57eac214da540 100644
--- a/src/ia32/macro-assembler-ia32.h
+++ b/src/ia32/macro-assembler-ia32.h
@@ -583,6 +583,12 @@ class MacroAssembler: public Assembler {
   // 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
 
@@ -941,6 +947,11 @@ class MacroAssembler: public Assembler {
   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());
   }