Add CMake support to the clang unittests.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125561 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index fb5933f..21775d1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -53,6 +53,8 @@
 
   add_definitions( -D__STDC_LIMIT_MACROS )
   add_definitions( -D__STDC_CONSTANT_MACROS )
+
+  set( CLANG_BUILT_STANDALONE 1 )
 endif()
 
 set(CLANG_RESOURCE_DIR "" CACHE STRING
@@ -214,3 +216,8 @@
 
 # TODO: docs.
 add_subdirectory(test)
+
+# FIXME: unittests require gtest.
+if( NOT CLANG_BUILT_STANDALONE )
+  add_subdirectory(unittests)
+endif()