Where to document supported versions of binutils?

[Michael Elizabeth Chastain]

We've learned that, on native i686-pc-linux-gnu, gdb has bugs
with binutils prior to binutils 2.13.  I saw this happen in my
test bed, and David Carlton also saw it happening on his system.

Where do we record this knowledge so that gdb users can see it?

There doesn't appear to be a obvious section in NEWS or README
for information like this.

Michael C