Subject: Fix range validation of integer commands with "unlimited".

Subject: Fix range validation of integer commands with "unlimited".

The range validation added by

  http://sourceware.org/ml/gdb-patches/2013-03/msg00767.html

Changes things to allow setting the command to INT_MAX or UINT_MAX
directly, with signed and unsigned commands respectively.  However,
that went a little bit too far, as in the cases of var_integer and
var_uinteger, those values are actually implementation detail.  It's
better to not expose them in the interface, and have users assume
those values mean "unlimited" too, so to be safer to expand the range
of the commands in the future if we want to.  Yes, it's pedantic, and
it's not likely users actually will do this, but MI frontends and
Python scripts might.

gdb/
2013-03-22  Pedro Alves  <palves@redhat.com>
	    Yao Qi  <yao@codesourcery.com>
	    Mark Kettenis  <kettenis@gnu.org>

	* cli/cli-setshow.c (do_set_command) <var_uinteger>:
	Don't let the user set the value to UINT_MAX directly.
	<var_integer>: Don't let the user set the value to INT_MAX
	directly.