[MSVC] Workaround missing search path for sanitizer headers.

This is to fix build errors "Cannot open include file:
'sanitizer/asan_interface.h'" when building LLVM with MSVC and
LLVM_USE_SANITIZER=Address.

asan_interface.h is not available in MSVC's search path, instead it is
located under %VCToolsInstallDir%/crt/src/sanitizer.
This is an alternate solution to https://reviews.llvm.org/D118159, to
avoid adding all internal crt sources to the header search paths.

Tested with visual studio 2019 v16.9.6 and visual studio 2022 v17.0.5

Reviewed By: aaron.ballman, rnk

Differential Revision: https://reviews.llvm.org/D118624