build: remove rtti for files using clang

Clang is usually compiled without runtime type information, so all files that use clang classes can't have rtti. This
change creates a separate CLANG_FILES variable which holds all clang files, so they can be compiled without rtti.

review id = 11

src/lib/CMakeLists.txt

@@ -1,3 +1,10 @@
+add_files(
+	CLANG_FILES
+
+	data/parser/clang.cpp
+	data/parser/clang.h
+)
+
 add_files(
 	LIB_FILES
 
@@ -25,9 +32,6 @@ add_files(
 	data/access/GraphAccess.cpp
 	data/access/GraphAccess.h
 
-	data/parser/clang.cpp
-	data/parser/clang.h
-
 	data/Edge.cpp
 	data/Edge.h
 	data/Element.cpp