[Bug target/121810] Out-of-range literal pool entry for MVE const vector

[rearnsha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121810

--- Comment #4 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
Fixed on trunk.  Leaving open while I consider whether this is worth a
back-port.