This patch enabled tsan for loongarch64 with 47-bit VMA layout. All
tests are passing.
Also adds assembly routines to enable setjmp/longjmp for loongarch64
on linux.
Reviewed By: dvyukov, SixWeining, #sanitizers
Differential Revision: https://reviews.llvm.org/D138489
XFAIL map32bit, define the maximum possible allocation size in
mmap_large.cpp.
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D105629