[InstCombine] re-commit r218721 icmp-select-icmp optimization

Takes care of the assert that caused build fails.
Rather than asserting the code checks now that the definition
and use are in the same block, and does not attempt
to optimize when that is not the case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219175 91177308-0d34-0410-b5e6-96231b3b80d8
gold plugin: Remap function arguments when creating a replacement function.

When creating an internal function replacement for use in an alias we were
not remapping the argument uses in the instructions to point to the new
arguments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219177 91177308-0d34-0410-b5e6-96231b3b80d8