Index: llvm/trunk/CMakeLists.txt
===================================================================
--- llvm/trunk/CMakeLists.txt
+++ llvm/trunk/CMakeLists.txt
@@ -1010,7 +1010,7 @@
 endif()
 
 # This allows us to deploy the Universal CRT DLLs by passing -DCMAKE_INSTALL_UCRT_LIBRARIES=ON to CMake
-if (MSVC)
+if (MSVC AND CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
   include(InstallRequiredSystemLibraries)
 endif()
 
Index: llvm/trunk/cmake/platforms/WinMsvc.cmake
===================================================================
--- llvm/trunk/cmake/platforms/WinMsvc.cmake
+++ llvm/trunk/cmake/platforms/WinMsvc.cmake
@@ -299,10 +299,3 @@
 # control which libraries they require.
 set(CMAKE_C_STANDARD_LIBRARIES "" CACHE STRING "" FORCE)
 set(CMAKE_CXX_STANDARD_LIBRARIES "" CACHE STRING "" FORCE)
-
-# CMake's InstallRequiredSystemLibraries module searches for a Visual Studio
-# installation in order to determine where to copy the required DLLs. This
-# installation won't exist when cross-compiling, of course, so silence the
-# resulting warnings about missing libraries.
-set(CMAKE_INSTALL_SYSTEM_RUNTIME_LIBS_NO_WARNINGS ON)
-