Upgrade to rustc-rayon-core 0.5.1

* [Fix a race with deadlock detection](rust-lang/rustc-rayon#15)
* [Cherry-pick changes from upstream rayon-core](rust-lang/rustc-rayon#16)
  - This also removes a few dependencies from rustc's tidy list.

Author: cuviper

Diff for: Cargo.lock

@@ -3199,14 +3199,12 @@ dependencies = [
 
 [[package]]
 name = "rustc-rayon-core"
-version = "0.5.0"
+version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67668daaf00e359c126f6dcb40d652d89b458a008c8afa727a42a2d20fca0b7f"
+checksum = "2f42932dcd3bcbe484b38a3ccf79b7906fac41c02d408b5b1bac26da3416efdb"
 dependencies = [
- "crossbeam-channel",
  "crossbeam-deque",
  "crossbeam-utils",
- "num_cpus",
 ]
 
 [[package]]

Diff for: src/tools/tidy/src/deps.rs

@@ -259,7 +259,6 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "constant_time_eq",
     "cpufeatures",
     "crc32fast",
-    "crossbeam-channel",
     "crossbeam-deque",
     "crossbeam-epoch",
     "crossbeam-utils",
@@ -294,7 +293,6 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "gimli",
     "gsgdt",
     "hashbrown",
-    "hermit-abi",
     "icu_list",
     "icu_list_data",
     "icu_locid",
@@ -328,7 +326,6 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "miniz_oxide",
     "nix",
     "nu-ansi-term",
-    "num_cpus",
     "object",
     "odht",
     "once_cell",