[destructuring] Adapting PatternRewriter to work in for-statements.

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index 94ece122c3b933f27638ff034d089f75763d9dd3..ffd3e74f9410c793230e6eb34715aa6f255e8038 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -3367,6 +3367,7 @@ class AstNodeFactory final BASE_EMBEDDED {
                                   Variable::Kind variable_kind,
                                   int start_position = RelocInfo::kNoPosition,
                                   int end_position = RelocInfo::kNoPosition) {
+    DCHECK_NOT_NULL(name);
     return new (zone_)
         VariableProxy(zone_, name, variable_kind, start_position, end_position);
   }