Originally committed as ffc3fb665d0a0dccd64cc8c803ad8cc1a0d5dfa1
Reverted in fcf2d5f40296be4e0f0e954001beb7814f97a212 due to an
assertion failure.
Original commit message:
Allow the folding even if there is an
intervening bitcast.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D106667