[Bug target/113955] Finish LRA transition for mips by removing -mlra

[xry111 at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113955

--- Comment #4 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to YunQiang Su from comment #3)
> -mlra has been set to default since it was added (2014).
> So, It is ok for us to remove it.

Then let's just remove it (maybe after GCC 14 release).