Fix PPC branch selection for counter-based branches

Although I had added some support for the BDZ/BDNZ branches into the selector
(in r158204), I had not correctly adjusted the condition at the top of the
loop. As a result, these branches were still essentially unsupported.

This fixes PR16086. Unfortunately, any test case would be very large (because
it would need to force the loop backedge to exceed the range of the 16-bit
immediate).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182385 91177308-0d34-0410-b5e6-96231b3b80d8
Drop @llvm.annotation and @llvm.ptr.annotation intrinsics during codegen.

The intrinsic calls are dropped, but the annotated value is propagated.

Fixes PR 15253

Original patch by Zeng Bin!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182387 91177308-0d34-0410-b5e6-96231b3b80d8