jniSavedProcessorRegAddr = framePtr.add(VM_JNICompiler.JNI_PR_OFFSET);
  public void setupIterator(VM_CompiledMethod compiledMethod, int instructionOffset, VM_Address framePtr) {    this.framePtr = framePtr;    // processor reg (PR) was saved at JNI_PR_OFFSET, and will be used to    // set processor reg upon return to java.  it must be reported during    // GC so it will be relocated, if necessary.    //    jniSavedProcessorRegAddr = framePtr.add(VM_JNICompiler.JNI_PR_OFFSET);    // return address into generated prolog must be relocated if the code object    // for that prolog/epilog is moved by GC    jniSavedReturnAddr       = framePtr.add(VM_JNICompiler.JNI_RETURN_ADDRESS_OFFSET);  } //- implements VM_GCMapIterator