diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ff4fa1527e93a..63ce91793ecdf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -41,15 +41,8 @@ jobs:
       matrix:
         include:
           - name: mingw-check
-            os: ubuntu-latest-xl
-            env: {}
-          - name: x86_64-gnu-llvm-10
-            os: ubuntu-latest-xl
+            os: ubuntu-latest
             env: {}
-          - name: x86_64-gnu-tools
-            env:
-              CI_ONLY_WHEN_SUBMODULES_CHANGED: 1
-            os: ubuntu-latest-xl
     timeout-minutes: 600
     runs-on: "${{ matrix.os }}"
     steps:
diff --git a/compiler/rustc_arena/src/lib.rs b/compiler/rustc_arena/src/lib.rs
index 2e8022d9880b2..258303b566251 100644
--- a/compiler/rustc_arena/src/lib.rs
+++ b/compiler/rustc_arena/src/lib.rs
@@ -11,7 +11,6 @@
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(no_crate_inject, attr(deny(warnings)))
 )]
-#![feature(dropck_eyepatch)]
 #![feature(new_uninit)]
 #![feature(maybe_uninit_slice)]
 #![feature(min_specialization)]
@@ -306,7 +305,7 @@ impl<T> TypedArena<T> {
     }
 }
 
-unsafe impl<#[may_dangle] T> Drop for TypedArena<T> {
+unsafe impl<T> Drop for TypedArena<T> {
     fn drop(&mut self) {
         unsafe {
             // Determine how much was filled.
diff --git a/compiler/rustc_index/src/lib.rs b/compiler/rustc_index/src/lib.rs
index 0093fa5e562af..8fb28343595ae 100644
--- a/compiler/rustc_index/src/lib.rs
+++ b/compiler/rustc_index/src/lib.rs
@@ -4,7 +4,6 @@
 #![feature(iter_zip)]
 #![feature(unboxed_closures)]
 #![feature(test)]
-#![feature(fn_traits)]
 
 pub mod bit_set;
 pub mod vec;
diff --git a/compiler/rustc_interface/src/lib.rs b/compiler/rustc_interface/src/lib.rs
index c7424b9e2a120..9c3607a600410 100644
--- a/compiler/rustc_interface/src/lib.rs
+++ b/compiler/rustc_interface/src/lib.rs
@@ -1,6 +1,5 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
-#![feature(internal_output_capture)]
 #![feature(nll)]
 #![feature(once_cell)]
 #![recursion_limit = "256"]
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index 573fa913d680a..95f06ab60d42d 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -23,17 +23,14 @@
 //! This API is completely unstable and subject to change.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
-#![feature(allocator_api)]
 #![feature(array_windows)]
 #![feature(assert_matches)]
 #![feature(backtrace)]
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(core_intrinsics)]
-#![feature(discriminant_kind)]
 #![feature(if_let_guard)]
 #![feature(never_type)]
-#![feature(extern_types)]
 #![feature(new_uninit)]
 #![feature(nll)]
 #![feature(once_cell)]