i386 vs i686

[Anders F Björklund]

Certain platforms report their "machine" (or `uname -m`)
as "i686" rather than "i386" like Darwin/FreeBSD does...

This arch should probably be converted to "i386" as well,
or else the variants and binaries won't match the other ?

	set arch $tcl_platform(machine)
	if {$arch == "Power Macintosh"} {
		set arch "powerpc"
	}
	if {$arch == "i686" || $arch == "x86"} {
		set arch "i386"
	}

Occasionally someone tries to use the variant "intel"
(which doesn't exist), so maybe that should somehow
be made into yet another synonym for "i386" as well ?
(interestingly, the darwin8 cross-compilers use i686)

--anders