Handle empty message in static_asserts.

llvm-svn: 281287
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 0cc03c7..8cbedd0 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -1243,8 +1243,9 @@
 bool CursorVisitor::VisitStaticAssertDecl(StaticAssertDecl *D) {
   if (Visit(MakeCXCursor(D->getAssertExpr(), StmtParent, TU, RegionOfInterest)))
     return true;
-  if (Visit(MakeCXCursor(D->getMessage(), StmtParent, TU, RegionOfInterest)))
-    return true;
+  if (StringLiteral *Message = D->getMessage())
+    if (Visit(MakeCXCursor(Message, StmtParent, TU, RegionOfInterest)))
+      return true;
   return false;
 }