Don't report any errors in lower_intrinsics. They should have been typecked before.

compiler/rustc_mir_transform/src/errors.rs

@@ -258,10 +258,3 @@ pub(crate) struct MustNotSuspendReason {
     pub span: Span,
     pub reason: String,
 }
-
-#[derive(Diagnostic)]
-#[diag(mir_transform_simd_shuffle_last_const)]
-pub(crate) struct SimdShuffleLastConst {
-    #[primary_span]
-    pub span: Span,
-}