CMake: Hopefully unbreak the build by mimicking the changes on the
other build system about the new C_INCLUDE_DIRS configure option.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86960 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 794e8e9..839def7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -70,6 +70,9 @@
     CACHE STRING "Semicolon-separated list of targets to build, or \"all\".")
 endif( MSVC )
 
+set(C_INCLUDE_DIRS "" CACHE STRING
+  "Colon separated list of directories clang will search for headers.")
+
 set(LLVM_TARGET_ARCH "host"
   CACHE STRING "Set target to use for LLVM JIT or use \"host\" for automatic detection.")