#484 Fix for GAS output syntax Inbox

[Atirut Wattanamongkol]

Came up with this patch while working on finding the holy grail that
is "Z80 C compiler + Binutils". It's lacking polish, but it does get a
simple hello world program to assemble with GAS. I'm still figuring
out if the section and symbol names can be overridden to take
advantage of the > RAM AT > ROM stuff in GNU ld, but I thought that
I should send this patch in to get some feedback.

P lease note that the patch has some unrelated changes because I forgot go disable whitespace trimming on my end.

[Philipp Klaus Krause]

I don't know much about GAS, but from its documentation, and for consistency, the patch looks like is make sense. I've picked some parts of it in [r15419]. I've left out the section stuff, since I'm less confident about it, and also removed some rarely-used directives.
Please have a look at [r15419] or later, and see if this is helpful to you.

P.S.: z88dk just has sdcc emit asxxxx syntax, then translates that to their desired one by custom peephole optimizer rules.