[Bug target/61749] arm_neon.h "_lane" and "_n" intrinsics can cause ICEs

["ktkachov at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61749

--- Comment #3 from ktkachov at gcc dot gnu.org ---
vqdmlal_lane_s16 expects an immediate/literal lane number as the fourth
argument and the builtin expansion code in aarch64-builtins.c is actually
equipped to error out when given a variable (in the SIMD_ARG_CONSTANT case of
aarch64_simd_expand_args).

However the type qualifiers for vqdmlal_lane_s16 are the QUADOP qualifiers
which don't enforce qualifier_immediate on the builtin, thus falling into the
SIMD_ARG_COPY_TO_REG and later on failing the CONST_INT_P assert when
processing the lane numbers.

If I give qualifier_immediate to the 4th argument I get a more helpful:
error: incompatible type for argument 4, expected 'const int'
message but the compiler still tries to proceed and ends up ICEing anyway.