[TSAN] add support for riscv64 (#68735)

Implements for sv39 and sv48 VMA layout.

Userspace only has access to the bottom half of vma range. The top half
is used by kernel. There is no dedicated vsyscall or heap segment.
PIE program is allocated to start at TASK_SIZE/3*2. Maximum ASLR is
ARCH_MMAP_RND_BITS_MAX+PAGE_SHIFT=24+12=36 Loader, vdso and other
libraries are allocated below stack from the top.

Also change RestoreAddr to use 4 bits to accommodate MappingRiscv64_48

Reviewed by: MaskRay, dvyukov, asb, StephenFan, luismarques, jrtc27,
hiraditya, vitalybuka

Differential Revision: https://reviews.llvm.org/D145214



D145214 was reverted because one file was missing in the latest commit.
Luckily the file was there in the previous commit, probably the author
missed uploading that file with latest commit.

Co-authored-by: Alex Fan <alex.fan.q@gmail.com>