Auto merge of #91743 - cjgillot:enable_mir_inlining_inline_all, r=oli-obk

Enable MIR inlining

Continuation of https://github.com/rust-lang/rust/pull/82280 by `@wesleywiser.`

#82280 has shown nice compile time wins could be obtained by enabling MIR inlining.
Most of the issues in https://github.com/rust-lang/rust/issues/81567 are now fixed,
except the interaction with polymorphization which is worked around specifically.

I believe we can proceed with enabling MIR inlining in the near future
(preferably just after beta branching, in case we discover new issues).

Steps before merging:
- [x] figure out the interaction with polymorphization;
- [x] figure out how miri should deal with extern types;
- [x] silence the extra arithmetic overflow warnings;
- [x] remove the codegen fulfilment ICE;
- [x] remove the type normalization ICEs while compiling nalgebra;
- [ ] tweak the inlining threshold.

compiler/rustc_monomorphize/src/collector.rs

@@ -730,7 +730,8 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                             def_id,
                             substs,
                             ty::ClosureKind::FnOnce,
-                        );
+                        )
+                        .expect("failed to normalize and resolve closure during codegen");
                         if should_codegen_locally(self.tcx, &instance) {
                             self.output.push(create_fn_mono_item(self.tcx, instance, span));
                         }