[COFF, ARM64] Implement support for SEH extensions __try/__except/__finally

Authored by mgrang on Jan 16 2019, 11:52 AM.


[COFF, ARM64] Implement support for SEH extensions try/except/__finally

This patch supports MS SEH extensions try/except/__finally. The intrinsics localescape and localrecover are responsible for communicating escaped static allocas from the try block to the handler.

We need to preserve frame pointers for SEH. So we create a new function/property HasLocalEscape.

Reviewers: rnk, compnerd, mstorsjo, TomTan, efriedma, ssijaric

Reviewed By: rnk, efriedma

Subscribers: smeenai, jrmuizel, alex, majnemer, ssijaric, ehsan, dmajor, kristina, javed.absar, kristof.beyls, chrib, llvm-commits

Differential Revision: https://reviews.llvm.org/D53540

llvm-svn: 351370