Make configure check for minimum required version of IPC::Run.

Per the discussion around 3eb1f4d, let's have configure verify that
the available IPC::Run version is at least 0.79, the agreed-on minimum.
It seems unlikely that this could bite anybody anymore, but it's useful
as documentation.  (Based on that, there's little need to back-patch.)

For consistency, also supply a minimum version for the other Perl
module we have an explicit check for, Time::HiRes.  I used the
version that ships with Perl 5.8.3.

Discussion: https://postgr.es/m/E1mYY6Z-0006OL-QN@gemulon.postgresql.org

Author: tglsfdc

configure

@@ -19255,6 +19255,8 @@ if test "$enable_tap_tests" = yes; then
   if test -z "$PROVE"; then
     # Test::More and Time::HiRes are supposed to be part of core Perl,
     # but some distros omit them in a minimal installation.
+    # The required minimum versions are all quite ancient now, but specify
+    # them anyway for documentation's sake.
 
 
 
@@ -19308,7 +19310,7 @@ fi
 
 if test "x$PERL" != x; then
   ax_perl_modules_failed=0
-  for ax_perl_module in 'IPC::Run' 'Test::More 0.87' 'Time::HiRes' ; do
+  for ax_perl_module in 'IPC::Run 0.79' 'Test::More 0.87' 'Time::HiRes 1.52' ; do
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for perl module $ax_perl_module" >&5
 $as_echo_n "checking for perl module $ax_perl_module... " >&6; }
 

configure.ac

@@ -2348,7 +2348,9 @@ if test "$enable_tap_tests" = yes; then
   if test -z "$PROVE"; then
     # Test::More and Time::HiRes are supposed to be part of core Perl,
     # but some distros omit them in a minimal installation.
-    AX_PROG_PERL_MODULES([IPC::Run Test::More=0.87 Time::HiRes], ,
+    # The required minimum versions are all quite ancient now, but specify
+    # them anyway for documentation's sake.
+    AX_PROG_PERL_MODULES([IPC::Run=0.79 Test::More=0.87 Time::HiRes=1.52], ,
       [AC_MSG_ERROR([Additional Perl modules are required to run TAP tests])])
   fi
   # Now make sure we know where prove is