[libclang] Do the ConcurrencyCheck at the beginning of clang_findReferencesInFile.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145455 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CIndexHigh.cpp b/tools/libclang/CIndexHigh.cpp
index a2a5854..a4f85b4 100644
--- a/tools/libclang/CIndexHigh.cpp
+++ b/tools/libclang/CIndexHigh.cpp
@@ -343,6 +343,12 @@
     return;
   }
 
+  ASTUnit *CXXUnit = cxcursor::getCursorASTUnit(cursor);
+  if (!CXXUnit)
+    return;
+
+  ASTUnit::ConcurrencyCheck Check(*CXXUnit);
+
   if (cursor.kind == CXCursor_MacroDefinition ||
       cursor.kind == CXCursor_MacroExpansion) {
     findMacroRefsInFile(cxcursor::getCursorTU(cursor),
@@ -370,9 +376,6 @@
     return;
   }
 
-  ASTUnit *CXXUnit = cxcursor::getCursorASTUnit(cursor);
-  ASTUnit::ConcurrencyCheck Check(*CXXUnit);
-
   findIdRefsInFile(cxcursor::getCursorTU(cursor),
                    refCursor,
                    static_cast<const FileEntry *>(file),