Support -fstack-clash-protection for x86
Implement protection against the stack clash attack  through inline stack
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC.
This extends the existing probe-stack' mechanism with a special value inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
This a recommit of 39f50da2a357a8f685b3540246c5d762734e035f with proper LiveIn
declaration, better option handling and more portable testing.
Differential Revision: https://reviews.llvm.org/D68720