arm: further fix overloading of MVE vaddq[_m]_n intrinsic

arm: further fix overloading of MVE vaddq[_m]_n intrinsic

It was observed that in tests `vaddq_m_n_[s/u][8/16/32].c`, the _Generic
resolution would fall back to the `__ARM_undef` failure state.

This is a regression since `dc39db873670bea8d8e655444387ceaa53a01a79` and
`6bd4ce64eb48a72eca300cb52773e6101d646004`, but it previously wasn't
identified, because the tests were not checking for this kind of failure.

The above commits changed the definitions of the intrinsics from using
`[u]int[8/16/32]_t` types for the scalar argument to using `int`. This
allowed `int` to be supported in user code through the overloaded
`#defines`, but seems to have broken the `[u]int[8/16/32]_t` types

The solution implemented by this patch is to explicitly use a new
_Generic mapping from all the `[u]int[8/16/32]_t` types for int. With this
change, both `int` and `[u]int[8/16/32]_t` parameters are supported from
user code and are handled by the overloading mechanism correctly.

Note that in these scalar cases it is safe to pass the raw p<n>, rather
than the typeof-ed __p<n>, because we are not at risk of the _Generics
being exponentially expanded on the `n` scalar argument to an `_n`
intrinsic. Using p<n> instead will give a more accurate error message
to the user, should something be wrong with that argument.

gcc/ChangeLog:
	PR target/96795
	* config/arm/arm_mve.h (__arm_vaddq_m_n_s8): Change types.
	(__arm_vaddq_m_n_s32): Likewise.
	(__arm_vaddq_m_n_s16): Likewise.
	(__arm_vaddq_m_n_u8): Likewise.
	(__arm_vaddq_m_n_u32): Likewise.
	(__arm_vaddq_m_n_u16): Likewise.
	(__arm_vaddq_m): Fix Overloading.
	(__ARM_mve_coerce3): New.