filenames had to be unquoted and also had to contain a / or .,
while others had to have no / and no . or be quoted, whereas
arbitrary machine symbols could always be optionally quoted,
which was kind of backwards.
Now, all filesnames use the same rules: quoted, or with a / or .
Arbitrary words can no longer be quoted unless the grammar specifically
allows it, which it now does for filenames, locator values, locator
defaults, compile-with, ident, makeoptions, and options.
Also, locator name symbols can be quoted, so mac68k's "no drq" locator
still works. ("no drq" doesn't appear in any machine description so I
presume it's just for the dmesg. )