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

[Hau Hsu via llvm-commits]

================
@@ -186,7 +189,7 @@
 #  elif SANITIZER_FREEBSD && defined(__aarch64__)
 #    define ASAN_SHADOW_OFFSET_CONST 0x0000800000000000
 #  elif SANITIZER_RISCV64
-#    define ASAN_SHADOW_OFFSET_CONST 0x0000000d55550000
+#    define ASAN_SHADOW_OFFSET_DYNAMIC
----------------
hau-hsu wrote:

We want it to be like windows that uses dynamic offset instead of a fixing value:
```
#  elif SANITIZER_WINDOWS64
#    define ASAN_SHADOW_OFFSET_DYNAMIC
```

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