Rollup merge of #118693 - saethlin:alignment-check-symbol-reachable, r=bjorn3

Tell MirUsedCollector that the pointer alignment checks calls its panic symbol

Fixes https://github.com/rust-lang/rust/pull/118683 (not an issue, but that PR is a basically a bug report)

When we had `panic_immediate_abort` start adding `#[inline]` to this panic function, builds started breaking because we failed to write up the MIR assert terminator to the correct panic shim. Things happened to work before by pure luck because without this feature enabled, the function we're inserting calls to is `#[inline(never)]` so we always generated code for it.

r? bjorn3

compiler/rustc_monomorphize/src/collector.rs

@@ -844,6 +844,9 @@ fn visit_terminator(&mut self, terminator: &mir::Terminator<'tcx>, location: Loc
             mir::TerminatorKind::Assert { ref msg, .. } => {
                 let lang_item = match &**msg {
                     mir::AssertKind::BoundsCheck { .. } => LangItem::PanicBoundsCheck,
+                    mir::AssertKind::MisalignedPointerDereference { .. } => {
+                        LangItem::PanicMisalignedPointerDereference
+                    }
                     _ => LangItem::Panic,
                 };
                 push_mono_lang_item(self, lang_item);