[compiler-rt] [compiler-rt] Reinstate removal of CRT choice flags from CMAKE_*_FLAGS* (PR #67935)

[Martin Storsjö via llvm-commits]

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@@ -375,6 +375,25 @@ endif()
 if(MSVC)
   # FIXME: In fact, sanitizers should support both /MT and /MD, see PR20214.
   set(CMAKE_MSVC_RUNTIME_LIBRARY MultiThreaded)
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mstorsjo wrote:

Because Microsoft haven’t yet upstreamed their changes where they make it possible to build the sanitizers with any CRT. The code here, in its current state, only support this one setting - allegedly.

https://github.com/llvm/llvm-project/pull/67935