hwasan: enable mmap interception (no tagging used)

This enables HWASan interception for mmap, to prevent users from allocating in the shadow memory regions. For compatibility, it does not use pointer tagging, nor does it allow MAP_FIXED with a tagged address.

This patch initializes the common interceptors, but that should be a no-op (except for the mmap interceptor), due to the disable-by-default nature of hwasan_platform_interceptors.h (from D150708). As the first patch to utilize this common interceptor machinery for HWASan, it also defines some macros (e.g., COMMON_INTERCEPT_FUNCTION) that will be useful as future interceptors are enabled.

TestCases/Posix/mmap_write_exec.cpp now passes for HWASan.

Reviewed By: kstoimenov, vitalybuka

Differential Revision: D151262