[AST] Make header standalone.

Most implementations get ptrdiff_t transitively, some don't. Explicitly
include cstddef.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@293488 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/AST/ASTVector.h b/include/clang/AST/ASTVector.h
index 9ae5fd62c65a1d73fa2e7e4444de7ee3d3def3ca..717a9e9dff340288cd3b6d6fbc4828c0d5d6563f 100644 (file)
--- a/include/clang/AST/ASTVector.h
+++ b/include/clang/AST/ASTVector.h
@@ -22,6 +22,7 @@
 #include "llvm/ADT/PointerIntPair.h"
 #include "llvm/Support/type_traits.h"
 #include <algorithm>
+#include <cstddef>
 #include <cstring>
 #include <memory>