Add a regression test

tests/mir-opt/inline/auxiliary/wrapper.rs

@@ -0,0 +1,10 @@
+//@ no-prefer-dynamic
+//@ compile-flags: -O
+
+pub trait Compare {
+    fn eq(self);
+}
+
+pub fn wrap<A: Compare>(a: A) {
+    Compare::eq(a);
+}

tests/mir-opt/inline/recursion_limit_prevents_cycle_discovery.rs

@@ -0,0 +1,54 @@
+//@ aux-build: wrapper.rs
+//@ compile-flags: -Zmir-opt-level=2 -Zinline-mir
+// skip-filecheck
+
+// This is a regression test for https://github.com/rust-lang/rust/issues/146998
+
+extern crate wrapper;
+use wrapper::{Compare, wrap};
+
+pub struct BundleInner;
+
+impl Compare for BundleInner {
+    fn eq(self) {
+        lots_of_calls();
+        wrap(Resource::ExtensionValue);
+    }
+}
+
+pub enum Resource {
+    Bundle,
+    ExtensionValue,
+}
+
+impl Compare for Resource {
+    fn eq(self) {
+        match self {
+            Self::Bundle => wrap(BundleInner),
+            Self::ExtensionValue => lots_of_calls(),
+        }
+    }
+}
+
+macro_rules! units {
+    ($($n: ident)*) => {
+        $(
+            struct $n;
+
+            impl Compare for $n {
+                fn eq(self) {  }
+            }
+
+            wrap($n);
+        )*
+    };
+}
+
+fn lots_of_calls() {
+    units! {
+        O1 O2 O3 O4 O5 O6 O7 O8 O9 O10 O11 O12 O13 O14 O15 O16 O17 O18 O19 O20
+        O21 O22 O23 O24 O25 O26 O27 O28 O29 O30 O31 O32 O33 O34 O35 O36 O37 O38 O39 O40
+        O41 O42 O43 O44 O45 O46 O47 O48 O49 O50 O51 O52 O53 O54 O55 O56 O57 O58 O59 O60
+        O61 O62 O63 O64 O65
+    }
+}