New test program, tst_grow_header.c, to test header extent growth

Author: wkliao

test/testcases/Makefile.am

@@ -95,9 +95,10 @@ TESTPROGRAMS = file_create_open \
                error_precedence \
                tst_free_comm \
                flexible_var \
-	       test_get_varn \
-	       tst_del_attr \
-	       tst_redefine
+	       	   test_get_varn \
+	       	   tst_del_attr \
+	       	   tst_redefine \
+	       	   tst_grow_header
 
 M4_SRCS      = put_all_kinds.m4 \
                erange_fill.m4 \