[Bug target/55212] [SH] Switch to LRA

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55212

--- Comment #94 from Oleg Endo <olegendo at gcc dot gnu.org> ---
Kaz, do you think we can enable LRA by default for GCC 6?

Some early results from the AMS optimization show new R0 spill failures.  For
example, AMS uses @(R0,Rn) address modes more often.  Although I still would
like to try this R0 prealloc pass, I don't know when I will have time for that.
 Enabling LRA might be easier.