[LTO] Move ChangeLog.lto into the GCC sub directory

[Andrew Pinski]

> CodeSourcery's usual practice is one top-level ChangeLog.  Since Kazu
> committed the first patch, we did it that way.  If other LTO
> contributors hate that we'll change it, but there's no reason to change
> it just for the sake of changing it.

I was proposing to following how tree-ssa was done which was multiple
ChangeLog files in each directory (which has a normal ChangeLog).
Which make life easier to figure out what changed in that directory.

Also it allows for easier merges back into the mainline

Also most other branches I have seen (except for CodeSourcery's branches)
have multiple ChangeLogs.

Also isn't most of CodeSourcery's branches more of a release branch rather
than a developmental branch?

Thanks,
Andrew Pinski