Minor regression due to recent IRA changes

[Oleg Endo]

On Thu, 2020-03-05 at 08:51 -0700, Jeff Law wrote:
> 
> FWIW I've got an sh4/sh4eb bootstrap and regression test running with
> HONOR_REG_ALLOC_ORDER defined.  As Vlad mentioned, that may be a
> viable workaround.
> 

I've had a look at the good old CSiBE code size results and poked at
some of the cases.  Overall, it seems to help code quality when
HONOR_REG_ALLOC_ORDER is defined on SH.

sum:  3383449 -> 3379629    -3820 / -0.112903 %
avg: -212.222222 / -0.271573 %
max: flex-2.5.31  253514 -> 253718        +204 / +0.080469 %
min: bzip2-1.0.2   67202 -> 65938        -1264 / -1.880896 %


However, even with HONOR_REG_ALLOC_ORDER defined, the simple test case
from PR 81426 https://gcc.gnu.org/bugzilla/attachment.cgi?id=47159
fails to compile without -mlra (use options -m4 -matomic-model=soft-gusa on regular non-linux sh-elf cross compiler).

How about the bootstrap, Jeff?  Did it help anything?

Cheers,
Oleg