[OpenMP] [cmake] Don't use -fno-semantic-interposition on Windows (#81113)

This was added in 4b7beab4187ab0766c3d7b272511d5751431a8da. When the
flag was added implicitly elsewhere, it was added via
llvm/cmake/modules/HandleLLVMOptions.cmake, where it wasn't added on
Windows/Cygwin targets.

This avoids one warning per object file in OpenMP.

GitOrigin-RevId: 72f04fa0734f8559ad515f507a4a3ce3f461f196
1 file changed