[perl #88496] missing dependencies in perl core makefiles

[perl #88496] missing dependencies in perl core makefiles

I have spotted a couple of missing dependencies in the makefiles
utils/Makefile.SH and x2p/Makefile.SH that prevent json_pp, s2p,
psed, and find2perl from being rebuilt after configuration changes.

This could cause trouble if the install prefix has been changed,
so that the shebang line of these scripts from a previous build
no longer matches the target location of the perl binary.

A workaround would be to always "make clean" after changes to
the configuration, which sounds reasonable anyway. That said,
most of the other tools do have config.sh properly listed as a
dependency and I don't see why those four should not.

I have attached a small patch against perl-5.13.11 to fix this.
The bug is also present in the latest stable release as of this
writing, perl-5.12.3, except that json_pp is not included there.