Clang: Fix compilation on Windows

...for LLVM snapshots (http://llvm.org/builds).

Check for lib/libclang.* if lib/clang.* is not found.

Change-Id: I6e24ac0fe696153626ded1ed3a7db85ce8d7b0f2
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/clangcodemodel/test/completiontesthelper.h

@@ -32,11 +32,12 @@
 
 #ifdef WITH_TESTS
 
+#include "../clangcompleter.h"
+
 #include <QObject>
 #include <QTextDocument>
 #include <texteditor/basetexteditor.h>
 #include <cplusplus/CppDocument.h>
-#include <clangcompleter.h>
 
 namespace TextEditor { class IAssistProposal; }