[FastISel][AArch64] Factor out ANDWri instruction generation into a helper function. NFCI.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216199 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64] Run a peephole pass right after AdvSIMD pass.
The AdvSIMD pass may produce copies that are not coalescer-friendly. The
peephole optimizer knows how to fix that as demonstrated in the test case.

<rdar://problem/12702965>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216200 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead code. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216201 91177308-0d34-0410-b5e6-96231b3b80d8
Respect LibraryInfo in populateLTOPassManager and use it. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216203 91177308-0d34-0410-b5e6-96231b3b80d8