This adds ISel support for lifetime markers in opt levels above O0.
It also updates the arm64-irtranslator test, and updates some AArch64 tests that
use them for added coverage.
It also adds a testcase taken from the X86 codegen tests which verified a bug
caused by lifetime markers + stack colouring in the past. This is intended to
make sure that GISel doesn't re-introduce the bug.
(This is basically a straight copy from what SelectionDAG does in
SelectionDAGBuilder.cpp)
https://reviews.llvm.org/D57187
llvm-svn: 352410