Move GetMBBSymbol up to AsmPrinter and make printBasicBlockLabel use it so that
we only have one place that decides what to name bb labels. Hopefully various
clients of printBasicBlockLabel can start using GetMBBSymbol instead.
llvm-svn: 81652
this means that it can only lower one MachineInstr to one MCInst. To
make this fly, we need to pull out handling of MO_GOT_ABSOLUTE_ADDRESS
(which generates an implicit label) out of X86MCInstLower.
llvm-svn: 81629