RFC: patch to build GCC for arm with LRA

[Yvan Roux]

Hi,

> Fair enough - we should just fix the test and move on.

Done.

> I would suggest in addition a transitional command-line option to switch
> between LRA and reload as a temporary measure so that folks can do some more
> experimenting for AArch32.

I've a patch which fixes the REG_NOTE issues, it's still under
validation, but seems to work.  I'll add the -mlra option to switch
between LRA and reload, but my question is, will LRA be enabled by
default or not, as we still have the Thumb issue ? Maybe switching LRA
on only in ARM mode is a good trade off, but in that case what is the
best way to do it ? (I'll pass a full validation when we'll be agree
on that point)

Thanks,
Yvan