[compiler-rt] [llvm] [RISCV][sanitizer] Fix sanitizer support for different virtual memory layout (PR #66743)

[Luís Marques via llvm-commits]

luismarques wrote:

> Test result: The test baseline is sv39 mode, without any commits in the PR. There are only 2 new failures for sv57:
> 
> ```
> TestCases/Linux/allocator_oom_test.cpp
> TestCases/Linux/quarantine_size_mb.cpp
> ```
> 
> After quick triage I think they are because the required memory is too large in sv57 mode, the original test conditions won't work. I'll have another PR if necessary later.

In my testing, the quarantine_size_mb also fails with this patch for sv39, whereas before it would pass for sv39, so I guess the problem isn't the memory size.

https://github.com/llvm/llvm-project/pull/66743