Set ZERO_AR_DATE=1 when running libtool.

test/mac/libtool-zero/mylib.c

Index: test/mac/libtool-zero/mylib.c
===================================================================
--- test/mac/libtool-zero/mylib.c	(working copy)
+++ test/mac/libtool-zero/mylib.c	(working copy)
@@ -2,6 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-int main() {
-  return 0;
+int my_foo(int x) {
+  return x + 1;
 }
Property changes on: test/mac/libtool-zero/mylib.c
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+LF
\ No newline at end of property