[hwasan] Update (Post-)DominatorTreeAnalysis and LoopAnalysis incrementally (#66935)

HWAddressSanitizerPass::run sanitizes functions one by one. The
sanitization of each function - which may split blocks via
insertShadowTagCheck - may result in some cached analyses are invalid.
This matters because sanitizeFunction(F', FAM) may indirectly call the
global stack safety analysis, hence we need to make sure the analyses of
F are up to date.

Bug report: https://github.com/llvm/llvm-project/issues/66934