Questionable remaining use of badOopVal, potential for removal.

share/utilities/globalDefinitions.hpp:const intptr_t badOopVal = -1; // generic "bad oop" value
share/utilities/globalDefinitions.hpp:#define badOop (cast_to_oop(::badOopVal))
share/code/compiledIC.cpp: assert (cache == NULL || cache != (Metadata*)badOopVal, "invalid metadata");