pg should ignore u+200b zero width space

i had a hell of a night last night trying to figure out what was wrong
with an attempt to use on constraint.

this morning i tried again and it worked.

but pasting the failed line from .psql_history into psql still failed.

i had to resort to od(1) to discover a no break space showed up just
before on constraint in the failing lines.

pg should treat a no break space after whitespace as just more
whitespace.

i'm not sure about alone between printing characters, but definitely
immediately after current whitespace characters.

[sent directly to the list because the 'community login' form is b0rked.]

-JimC
-- 
James Cloos <cloos@jhcloos.com>         OpenPGP: 0x997A9F17ED7DAEA6