Is there a page somewhere about obsolete OS revisions ?

[Dennis Clarke via Gcc-help <gcc-help@xxxxxxxxxxx>]

    I have been searching around the documentation but I do not see 
where the --enable-obsolete happens for a given release. For example
in the "changes" for GCC 7.5.0 on Nov 14, 2019 :


    https://gcc.gnu.org/gcc-7/changes.html


    There I see RISC-V but no mention of Linux or FreeBSD. Just as an 
example. Lets suppose I dragged out some old old machine and installed
some old old dusty OS on it just for fun. Can I bootstrap GCC 7.5.0 or
so I need to go to GCC 4.7 and GNU binutils 2.23.1 ?  I have an Apple
PowerMac G5 quad and a SPARCStation 20 both running fine but no clear
idea what rev of GCC is best to bootstrap.

    Happy New Year and all that jazz.



--
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken
GreyBeard and suspenders optional