Implement SHA512, SM3 and SM4 intrinsics

[sayantn]

This PR implements all the SHA512, SM3 and SM4 intrinsics (rust-lang/rust#126624).

This also fixes a issue in stdarch-verify where it was silently not verifying most intrinsics as they were marked safe as part of target_feature_11.

[rustbot]

r? @Amanieu

rustbot has assigned @Amanieu.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[sayantn]

---- verify_all_signatures stdout ----
failed to verify `vdupq_n_p8`
  * mismatched arguments: PrimUnsigned(8) != PrimPoly(8)

@Amanieu this intrinsic should have p8 parameter right? Can we change this?

edit: looking into older docs show that it was always like that, I am changing it since p8 is just an alias for u8