More ABI changes

[Walter Bright]

Don Clugston wrote:
> However, even better would be to make this aspect of the ABI
> CPU-independent.
> 
> Define format to be:
> e HexExponent HexSignificand  for real and imaginary FP literals.
> c HexExponent HexSignificand HexExponent HexSignificand for complex FP
> literals.

You've given me a great idea. Why not just use the %A format? It 
portably formats the value into a machine independent hex format. All 
that needs to be done is to massage it to elide the non-identifier 
characters.

> I'll post a patch to do this when I get a chance. 

Not necessary, I've already done it.