Rollup merge of rust-lang#142078 - sayantn:more-intrinsics, r=workingjubilee

Add SIMD funnel shift and round-to-even intrinsics

This PR adds 3 new SIMD intrinsics

 - `simd_funnel_shl` - funnel shift left
 - `simd_funnel_shr` - funnel shift right
 - `simd_round_ties_even` (vector version of `round_ties_even_fN`)

TODO (future PR): implement `simd_fsh{l,r}` in miri, cg_gcc and cg_clif (it is surprisingly hard to implement without branches, the common tricks that rotate uses doesn't work because we have 2 elements now. e.g, the `-n&31` trick used by cg_gcc to implement rotate doesn't work with this because then `fshl(a, b, 0)` will be `a | b`)

[#t-compiler > More SIMD intrinsics](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/More.20SIMD.20intrinsics/with/522130286)

`@rustbot` label T-compiler T-libs A-intrinsics F-core_intrinsics
r? `@workingjubilee`

Author: GuillaumeGomez

src/intrinsic/simd.rs

@@ -780,6 +780,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             sym::simd_fsin => "sin",
             sym::simd_fsqrt => "sqrt",
             sym::simd_round => "round",
+            sym::simd_round_ties_even => "rint",
             sym::simd_trunc => "trunc",
             _ => return_error!(InvalidMonomorphization::UnrecognizedIntrinsic { span, name }),
         };
@@ -827,6 +828,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             | sym::simd_fsin
             | sym::simd_fsqrt
             | sym::simd_round
+            | sym::simd_round_ties_even
             | sym::simd_trunc
     ) {
         return simd_simple_float_intrinsic(name, in_elem, in_ty, in_len, bx, span, args);