[PATCH] Document Sparc64 configuration

[Rainer Orth]

Kelley Cook writes:

> All of these legitimate concerns would seem to be easily correctable with 
> the attached patch  (please note that this is only a suggestion -- it is not 
> addressed to config@gcc.gnu.org)

What do you want to achieve with this patch: canonicalize
e.g. sparcv9-sun-solaris2 to sparc64-sun-solaris2?  This doesn't work since
the changed cases are never used: sparc* without a vendor name is
canonicalized as sparc*-unknown, and sparc*-<vendor> is left as is.

	Rainer