Integrate maint patches #17421, #17424:

Integrate maint patches #17421, #17424:

on platforms like HP-UX that are subject to the ARG_ZERO_IS_SCRIPT
hack, $^X was improperly set to the script name when the script
was run via the PATH; argv[0] in that case shows up as the bare
name of the script rather than its fully qualified path, which
meant that the sanity check in the ARG_ZERO_IS_SCRIPT code fails
to recognize it as the running script name; fix tries to match
bare script name in that case (from Gisle Aas)

tweak change#17421 ($0 is full path to script even when script
is invoked via PATH almost everywhere except Windows)
p4raw-link: @17421 on //depot/maint-5.6/perl: 32099b6ba13a228ffd08d5c7359d07c687b11471

p4raw-id: //depot/perl@17425
p4raw-integrated: from //depot/maint-5.6/perl@17423 'edit in'
	t/op/magic.t (@17421..) 'merge in' toke.c (@16508..)