tm.texi fixes

[craig@jcb-sc.com]

>! pass to @code{cc1, cc1plus, f771, and the other language front ends}.

Not an appropriate usage of @code.  Suggest something like:

>! pass to the compilation phase of every supported language (@code{cc1}, @code{f771}, etc.).

Also, was simply renaming CC1_SPEC to COMPILE_SPEC considered?  That'd
be painful, but it looks like expecting programmers to read the docs
on what is now clearly a poorly named macro is likely to be at least
as painful in the long run -- because they often won't bother.  (I strongly
support the idea of using names properly.  If we're willing to use misleading
names for things, we might as well pick names like BV23G1, to save space
on disk.  ;-)

        tq vm, (burley)