Fix PHIElimination optimization that uses MBB->getBasicBlock.

The BasicBlock associated with a MachineBasicBlock does not necessarily
correspond to the code in the MBB.

Don't insert a new IR BasicBlock when splitting critical edges. We are not
supposed to modify the IR during codegen, and we should be able to do just
fine with a NULL BB.

llvm-svn: 88707
2 files changed
tree: 3024d490abd206bc8e26d6b68ea94b3b151f0abf
  1. clang/
  2. compiler-rt/
  3. llvm/