cmake: link release builds statically against run-time library on windows (use /MT instead of /MD)

This should fix the problem of snapshot builds created with MSVC 2012 not
working for users with MSVC 2010, etc.

Differential Revision: http://llvm-reviews.chandlerc.com/D2157

llvm-svn: 194589

llvm/cmake/modules/HandleLLVMOptions.cmake

@@ -5,6 +5,7 @@
 include(AddLLVMDefinitions)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
+include(LLVMProcessSources)
 
 if( CMAKE_COMPILER_IS_GNUCXX )
   set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
@@ -40,6 +41,15 @@ else()
   endif()
 endif()
 
+if(MSVC)
+  # Link release builds against the static runtime.
+  foreach(flag CMAKE_C_FLAGS_RELEASE CMAKE_C_FLAGS_RELWITHDEBINFO
+      CMAKE_C_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELEASE
+      CMAKE_CXX_FLAGS_RELWITHDEBINFO CMAKE_CXX_FLAGS_MINSIZEREL)
+    llvm_replace_compiler_option("${flag}" "/MD" "/MT")
+  endforeach()
+endif()  
+
 if(WIN32)
   if(CYGWIN)
     set(LLVM_ON_WIN32 0)