Obsolete p_secstodate.

This patch, relative to a tree with
<https://sourceware.org/ml/libc-alpha/2017-11/msg00797.html> (pending
review) applied, obsoletes p_secstodate, making the underlying
function __p_secstodate into a compat symbol not available for new
binaries or ports.  The calls in ns_print.c (part of incomplete
handling of TKEY) are changed to use %lu to print times instead of
trying to pretty-print the times any more.

Tested for x86_64.

	* resolv/res_debug.c (p_secstodate): Condition definition on
	[SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_27)].  Define
	directly as __p_secstodate, and as a compat symbol.  Do not use
	libresolv_hidden_def.
	* resolv/resolv.h (p_secstodate): Remove macro and function
	declaration.
	* resolv/ns_print.c (ns_sprintrrf): Print times with %lu, not
	using p_secstodate.
	* include/resolv.h (__p_secstodate): Do not use
	libresolv_hidden_proto.
	* resolv/Makefile (tests): Move tst-p_secstodate to ....
	(tests-internal): ... here.
	* resolv/tst-p_secstodate.c: Include <shlib-compat.h>.  Condition
	all contents on [TEST_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_27)]
	and declare and use __p_secstodate and use compat_symbol_reference
	in that case.
	[!TEST_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_27)] (do_test): Add
	implementation returning 77.

1 files changed, 3 insertions, 1 deletions

diff --git a/resolv/Makefile b/resolv/Makefile
index aff671042e..a98a84fa9e 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -55,7 +55,6 @@ tests += \
   tst-resolv-network \
   tst-resolv-res_init-multi \
   tst-resolv-search \
-  tst-p_secstodate \
 
 # These tests need libdl.
 ifeq (yes,$(build-shared))
@@ -77,6 +76,9 @@ endif
 # This test accesses __inet_ntop_length, an internal libc function.
 tests-internal += tst-inet_pton
 
+# This test accesses the __p_secstodate compat symbol.
+tests-internal += tst-p_secstodate
+
 # This test sends millions of packets and is rather slow.
 xtests += tst-resolv-qtypes