[clang] [llvm] [SystemZ] Global Stackprotector and associated location section (PR #169317)

[Dominik Steenken via cfe-commits]

dominik-steenken wrote:

@uweigand I updated the PR and, i think, incorporated all of your feedback. I did end up going via `getCmp`/`emitCmp`. It works, but does require adding a `SystemZISD` opcode in addition to the two machine pseudos that were already there. I was kind of hoping i woul dbe ablke to get away with dropping one of them, but i didn't see a way to do that.

I have also shortened many of the pseudo names. They were getting quite long (`LOAD_GLOBAL_STACK_GUARD_ADDRESS`), and i think i prefer the shorter names. They are slightly less clear though, so if you like, i can revert that particular change and go back to the long names.

https://github.com/llvm/llvm-project/pull/169317