Verify that phi instructions refer to MBBs in the CFG.

The machine code verifier no longer tolerates phi instructions with noop
operands. All MBBs on a phi instruction must be in the CFG.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82448 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed