bug#13033: 24.3.50; regression: read-file-name-internal handles "~" wrong

[Drew Adams]

> Can you tell me what happens when you do the following:
> 
> (completion--embedded-envvar-table "~" 'file-exists-p nil)
nil

> (completion--file-name-table "~" 'file-exists-p nil)
"~dradams/"

> (completion-file-name-table "~" 'file-exists-p nil)
"~dradams/"

All from emacs -Q.  In Emacs 24.2 and 23.4 they all return nil.