[Bug target/105090] BFI instructions are not generated on arm-none-eabi-g++

[rearnsha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105090

--- Comment #9 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
It looks like the compiler now merges b into a rather than a into b.  The
result is the same, though and we don't need an lsr this way.  Technically it
ought to be better.

But we do end up in a dance with the registers this way at present.  I suspect
it's due to not splitting DFmode regs as aggressively as we do DImode and then
ending up trying to re-form them later on for register allocation purposes.

Anyway, I don't think the lsr is essential to the test, so lets just remove
that from the test.