Do not remote duplicate entries from ldflags when generating ninja files as it changes behavior

test/ldflags-duplicates/lib1.c

Index: test/ldflags-duplicates/lib1.c
diff --git a/test/msvs/buildevents/main.cc b/test/ldflags-duplicates/lib1.c
similarity index 60%
copy from test/msvs/buildevents/main.cc
copy to test/ldflags-duplicates/lib1.c
index 03c0285a6cc856103f8adad4d35dc76e42a51042..a1322e73955c6001d1140fe30c32de9c05bff141 100644
--- a/test/msvs/buildevents/main.cc
+++ b/test/ldflags-duplicates/lib1.c
@@ -1,5 +1,6 @@
-// Copyright (c) 2014 Google Inc. All rights reserved.
+// Copyright (c) 2015 Google Inc. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-int main() {}
+void foo() {
+}