Revert r319482 and r319483 "[memcpyopt] Teach memcpyopt to optimize across basic blocks"
This caused PR35519.
> [memcpyopt] Teach memcpyopt to optimize across basic blocks
>
> This teaches memcpyopt to make a non-local memdep query when a local query
> indicates that the dependency is non-local. This notably allows it to
> eliminate many more llvm.memcpy calls in common Rust code, often by 20-30%.
>
> Fixes PR28958.
>
> Differential Revision: https://reviews.llvm.org/D38374
>
> [memcpyopt] Commit file missed in r319482.
>
> This change was meant to be included with r319482 but was accidentally
> omitted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319873
91177308-0d34-0410-b5e6-
96231b3b80d8