Rollup merge of #121247 - scottmcm:intrinsic-reminder, r=petrochenkov

Add help to `hir_analysis_unrecognized_intrinsic_function`

To help remind forgetful people like me what step they forgot.

(If this just ICE'd, https://github.com/rust-lang/compiler-team/issues/620 style, the stack trace would point me here, but since there's a "nice" error that information is lost.)

compiler/rustc_hir_analysis/messages.ftl

@@ -469,6 +469,7 @@ hir_analysis_unrecognized_atomic_operation =
 hir_analysis_unrecognized_intrinsic_function =
     unrecognized intrinsic function: `{$name}`
     .label = unrecognized intrinsic
+    .help = if you're adding an intrinsic, be sure to update `check_intrinsic_type`
 
 hir_analysis_unused_associated_type_bounds =
     unnecessary associated type bound for not object safe associated type

compiler/rustc_hir_analysis/src/errors.rs

@@ -143,6 +143,7 @@ pub struct WrongNumberOfGenericArgumentsToIntrinsic<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_unrecognized_intrinsic_function, code = E0093)]
+#[help]
 pub struct UnrecognizedIntrinsicFunction {
     #[primary_span]
     #[label]