cargo gets stuck compiling nlist crate

cargo fails to compile the latest version of nlist. This happens because rustc gets stuck in rustc_trait_selection::traits::project::normalize_projection_term.

This only happens at opt-level 2 and only when inline-mir is enabled. It successfully compiles with the following command:

cargo +nightly rustc --release -- -Z inline-mir=no

I used perf to see where the compiler is getting stuck. The following is the relevant part of the perf report:

Samples: 120K of event 'cycles', Event count (approx.): 111444101575
  Children      Self  Command  Shared Object                        Symbol
+   79.78%    79.71%  rustc    librustc_driver-24ace9b62cb3ceb9.so  [.] rustc_trait_selection::traits::project::normalize_projection_term
+   42.68%     0.00%  rustc    [unknown]                            [.] 0000000000000000
+   20.22%    20.20%  rustc    librustc_driver-24ace9b62cb3ceb9.so  [.] <rustc_trait_selection::traits::normalize::AssocTypeNormalizer as rustc_type_ir::fold::TypeFolder<rustc_middle::ty::context::TyCtxt>>::fold_ty
+    5.93%     0.00%  rustc    [unknown]                            [.] 0x0000000e00000000
+    5.59%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef69da0
+    5.49%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef72010
+    5.37%     0.00%  rustc    [unknown]                            [k] 0x0000001f00000021
+    2.87%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef71fd0
+    2.77%     0.00%  rustc    [unknown]                            [.] 0x0000001c00000000
+    2.67%     0.00%  rustc    [unknown]                            [.] 0x0000000000000001
+    1.45%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef6bc20
+    1.40%     0.00%  rustc    [unknown]                            [.] 0x00007f4990d71158
+    1.37%     0.00%  rustc    [unknown]                            [.] 0x00007f4990658190
+    1.28%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef62600
+    0.75%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef6a830
+    0.70%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef61210
+    0.67%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef6d050
+    0.66%     0.00%  rustc    [unknown]                            [.] 0x0000000100000003
     0.39%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef73ca0
     0.33%     0.00%  rustc    [unknown]                            [.] 0x000d2829ffffff01
     0.32%     0.00%  rustc    [unknown]                            [.] 0x00007f498ef69440

Start by reproducing the nlist build with cargo +nightly rustc --release at opt-level 2 and inline-mir enabled, then inspect the reported rustc_trait_selection::traits::project::normalize_projection_term path using the perf report as a guide. Done means the latest nlist version compiles without requiring -Z inline-mir=no.