perldiag: reflow an entry for better splain output
[perl #113932] Make UNIVERSAL::can("STDOUT"...) work

For consistency with the way method lookup works, UNIVERSAL::can(...)
should treat a bareword representing a filehandle as a lookup in the
IO::File package (or whichever package implements that filehandle
object).
[perl #118857] Test punct vars’ exemption from ‘once’ warnings
[perl #118525] Return B::HEK for B::CV::GV of lexical subs

A lexsub has a hek instead of a gv. Provide a ref to a PV for the name
in the new B::HEK class.
This crashed previously accessing the not existing SvFLAGS of the hek.
Revert "Allow => to quote built-in keywords across lines"

This reverts commit 5969c5766a5d3f6b42a5140548d7c3d6812fec8b.

It appears to be failing with non-mad builds.