[compiler-rt] [compiler-rt] Don't check COMPILER_RT_STANDALONE_BUILD for test deps (PR #83651)

[Vincent Lee via llvm-commits]

thevinster wrote:

Echo-ing the [comment](https://github.com/llvm/llvm-project/pull/66259#issuecomment-1726623392) made by @smeenai, checking for `COMPILER_RT_HAS_MSAN` or `COMPILER_RT_HAS_DFSAN` only checks whether the machine can support it, but not whether the user decides to build it (which ends up becoming a missing dep since we don't build for these sanitizers). Our workaround is to build it, but we don't need it, and it increases our build time. Have we thought about any other workarounds? 

https://github.com/llvm/llvm-project/pull/83651