Improve the Python bindings for libclang in a few ways, from Eli
Bendersky. Specifically: 

* Implemented a new function in libclang: clang_isAttribute

* Fixing TranslationUnit.get_includes to only go through the argument
* buffer when it contains something. This fixed a crash on Windows 

* clang_getFileName returns CXString, not char*. Made appropriate
* fixes in cindex.py - now the relevant tests pass and we can see the
* full locations correctly again (previously there was garbage in
* place of the file name) 
* Exposed clang_getCursorDisplayName to the python bindings



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/libclang.darwin.exports b/tools/libclang/libclang.darwin.exports
index 85dfcb6..daada6d 100644
--- a/tools/libclang/libclang.darwin.exports
+++ b/tools/libclang/libclang.darwin.exports
@@ -112,6 +112,7 @@
 _clang_getTypeDeclaration
 _clang_getTypeKindSpelling
 _clang_hashCursor
+_clang_isAttribute
 _clang_isConstQualifiedType
 _clang_isCursorDefinition
 _clang_isDeclaration