Index: llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
+++ llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
@@ -353,19 +353,6 @@
   append("/Zc:rvalueCast" CMAKE_CXX_FLAGS)
 
   if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    # Find and run MSVC (not clang-cl) and get its version. This will tell
-    # clang-cl what version of MSVC to pretend to be so that the STL works.
-    execute_process(COMMAND "$ENV{VSINSTALLDIR}/VC/bin/cl.exe"
-      OUTPUT_QUIET
-      ERROR_VARIABLE MSVC_COMPAT_VERSION
-      )
-    string(REGEX REPLACE "^.*Compiler Version ([0-9.]+) for .*$" "\\1"
-      MSVC_COMPAT_VERSION "${MSVC_COMPAT_VERSION}")
-    append("-fms-compatibility-version=${MSVC_COMPAT_VERSION}"
-      CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
-  endif()
-
-  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     # clang-cl and cl by default produce non-deterministic binaries because
     # link.exe /incremental requires a timestamp in the .obj file.  clang-cl
     # has the flag /Brepro to force deterministic binaries. We want to pass that