[llvm] Support: use Windows 10 RS1+ API if possible to make moves more atomic (PR #102240)

[Saleem Abdulrasool via llvm-commits]

compnerd wrote:

Hmm, seems that the support test was testing for the existing behaviour:
```
--
  | GTEST_OUTPUT=json:C:\ws\src\build\unittests\Support\.\SupportTests.exe-LLVM-Unit-63012-25-43.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=43 GTEST_SHARD_INDEX=25 C:\ws\src\build\unittests\Support\.\SupportTests.exe
  | --
  |  
  | Script:
  | --
  | C:\ws\src\build\unittests\Support\.\SupportTests.exe --gtest_filter=rename.ExistingTemp
  | --
  | C:\ws\src\llvm\unittests\Support\ReplaceFileTest.cpp(163): error: Expected equality of these values:
  | errc::permission_denied
  | Which is: generic:13
  | fs::openFileForRead(TargetTmp1FileName, Tmp1FD)
  | Which is: generic:2
  |  
  |  
  | C:\ws\src\llvm\unittests\Support\ReplaceFileTest.cpp:163
  | Expected equality of these values:
  | errc::permission_denied
  | Which is: generic:13
  | fs::openFileForRead(TargetTmp1FileName, Tmp1FD)
  | Which is: generic:2
```

https://github.com/llvm/llvm-project/pull/102240