Refactor ExternalReference::isolate_address() to not rely on Isolate::Current().

src/mips/regexp-macro-assembler-mips.h

 // Copyright 2011 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 211 matching lines @@
   inline void Pop(Register target);
 
   // Calls a C function and cleans up the frame alignment done by
   // by FrameAlign. The called function *is* allowed to trigger a garbage
   // collection, but may not take more than four arguments (no arguments
   // passed on the stack), and the first argument will be a pointer to the
   // return address.
   inline void CallCFunctionUsingStub(ExternalReference function,
                                      int num_arguments);
 
+  Isolate* isolate() const { return masm_->isolate(); }
 
   MacroAssembler* masm_;
 
   // Which mode to generate code for (ASCII or UC16).
   Mode mode_;
 
   // One greater than maximal register index actually used.
   int num_registers_;
 
   // Number of registers to output at the end (the saved registers
@@ skipping 10 matching lines @@
   Label stack_overflow_label_;
   Label internal_failure_label_;
 };
 
 #endif  // V8_INTERPRETED_REGEXP
 
 
 }}  // namespace v8::internal
 
 #endif  // V8_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_