[compiler-rt] [tsan][riscv] correct Go race detector mapping for RISC-V sv48 VMA (PR #154700)

[Thurston Dang via llvm-commits]

https://github.com/thurstond approved this pull request.

Drive-by comment, not necessary to fix in this patch: the shadow and metainfo regions are unnecessarily large relative to the app region (they only need to be 2x and 0.5x in size respectively).

https://github.com/llvm/llvm-project/pull/154700