Updated mangling specs

[Daveed Vandevoorde]

[...]
> You can either mangle the sequence of tokens after normalizing the
> parameter tokens (e.g., "J+10" and "L+10" are definitely equivalent
> if L and J are both first template parameters of the nontype kind),
> or you can construct a mangled representation of the tree structure
> representing the expression.  In the latter case, you might have
> constant-folded nondependent subexpressions.
> 
> The EDG front end does the former, but HP aC++ does the latter.

Actually, upon closer investigation it appears that EDG also does the 
latter, but only simple kinds of folding are applied: since I+1+2
is really (I+1)+2 no folding is done, but 1+2+I would be (1+2)+I and
we fold that to 3+I.

	Daveed