[libclang] Fix operations (token annotation, getting cursor, etc.) with a file region
inside an objc container that "contains" other file-level declarations.

When getting the array of file-level declarations that overlap with a file region,
we failed to report that the region overlaps with an objc container, if
the container had other file-level declarations declared lexically inside it.

Fix this by marking such declarations as "isTopLevelDeclInObjCContainer" in the AST
and handling them appropriately.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145109 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index de90c7b..2569e22 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -4293,6 +4293,14 @@
   if (BeginIt != DInfo.Decls.begin())
     --BeginIt;
 
+  // If we are pointing at a top-level decl inside an objc container, we need
+  // to backtrack until we find it otherwise we will fail to report that the
+  // region overlaps with an objc container.
+  while (BeginIt != DInfo.Decls.begin() &&
+         GetDecl(getGlobalDeclID(*DInfo.Mod, *BeginIt))
+             ->isTopLevelDeclInObjCContainer())
+    --BeginIt;
+
   ArrayRef<serialization::LocalDeclID>::iterator
     EndIt = std::upper_bound(DInfo.Decls.begin(), DInfo.Decls.end(),
                              EndLoc, DIDComp);