CMake: Tweak for Visual Studio 10 quirk at clang-standalone build.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125647 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 21775d1..63b7213 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -221,3 +221,12 @@
 if( NOT CLANG_BUILT_STANDALONE )
   add_subdirectory(unittests)
 endif()
+
+# Workaround for MSVS10 to avoid the Dialog Hell
+# FIXME: This could be removed with future version of CMake.
+if( CLANG_BUILT_STANDALONE AND MSVC_VERSION EQUAL 1600 )
+  set(CLANG_SLN_FILENAME "${CMAKE_CURRENT_BINARY_DIR}/Clang.sln")
+  if( EXISTS "${CLANG_SLN_FILENAME}" )
+    file(APPEND "${CLANG_SLN_FILENAME}" "\n# This should be regenerated!\n")
+  endif()
+endif()