Allow GN template collisions if they're the same.

tools/gn/parse_tree.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/parse_tree.h"
 
 #include <string>
 
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 322 matching lines @@
 
 const FunctionCallNode* FunctionCallNode::AsFunctionCall() const {
   return this;
 }
 
 Value FunctionCallNode::Execute(Scope* scope, Err* err) const {
   return functions::RunFunction(scope, this, args_.get(), block_.get(), err);
 }
 
 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());
 }
 
 Err FunctionCallNode::MakeErrorDescribing(const std::string& msg,
                                           const std::string& help) const {
   return Err(function_, msg, help);
 }
 
@@ skipping 171 matching lines @@
 
 Err UnaryOpNode::MakeErrorDescribing(const std::string& msg,
                                      const std::string& help) const {
   return Err(op_, msg, help);
 }
 
 void UnaryOpNode::Print(std::ostream& out, int indent) const {
   out << IndentFor(indent) << "UNARY(" << op_.value() << ")\n";
   operand_->Print(out, indent + 1);
 }