Allow GN template collisions if they're the same.

tools/gn/parse_tree.cc

Index: tools/gn/parse_tree.cc
diff --git a/tools/gn/parse_tree.cc b/tools/gn/parse_tree.cc
index 59b39f36cee9d90f1f075b7e7022b62ba74b0c4a..c4f78b7ce0768f9f7e7d025d112e1e25c7c31930 100644
--- a/tools/gn/parse_tree.cc
+++ b/tools/gn/parse_tree.cc
@@ -340,6 +340,8 @@ Value FunctionCallNode::Execute(Scope* scope, Err* err) const {
 }
 
 LocationRange FunctionCallNode::GetRange() const {
+  if (function_.type() == Token::INVALID)
+    return LocationRange();  // This will be null in some tests.
   if (block_)
     return function_.range().Union(block_->GetRange());
   return function_.range().Union(args_->GetRange());