[llvm-objdump] improve error reporting of bad mach-o ordinals

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217909 91177308-0d34-0410-b5e6-96231b3b80d8
[CodeGenPrepare][AddressingModeMatcher] The promotion mechanism was expecting
instructions when truncate, sext, or zext were created. Fix that.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217926 91177308-0d34-0410-b5e6-96231b3b80d8