now that we have a centralized place to do so, add some using declarations for
some common llvm types: stringref and smallvector.  This cleans up the codebase
quite a bit.

llvm-svn: 135576
diff --git a/clang/tools/libclang/CXString.h b/clang/tools/libclang/CXString.h
index f03a6b2..45d13eb 100644
--- a/clang/tools/libclang/CXString.h
+++ b/clang/tools/libclang/CXString.h
@@ -15,6 +15,7 @@
 #define LLVM_CLANG_CXSTRING_H
 
 #include "clang-c/Index.h"
+#include "clang/Basic/LLVM.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/SmallString.h"
 
@@ -31,7 +32,7 @@
 CXString createCXString(const char *String, bool DupString = false);
 
 /// \brief Create a CXString object from a StringRef.
-CXString createCXString(llvm::StringRef String, bool DupString = true);
+CXString createCXString(StringRef String, bool DupString = true);
 
 /// \brief Create a CXString object that is backed by a string buffer.
 CXString createCXString(CXStringBuf *buf);