[Bug target/115950] Missed SVE fold to INCP

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115950

--- Comment #5 from Richard Sandiford <rsandifo at gcc dot gnu.org> ---
Alternatively, I suppose we could say that svcntp_bN(svptrue_bN(), pg) etc.
should be folded to svcntp_bN(pg, pg) in gimple/expand, and then make the
INCP/DECP wrappers only match the equal-predicate version.