(DO NOT MERGE) Check that this fails in x86_64-gnu

Author: Zalathar

compiler/rustc_macros/src/try_from.rs

@@ -40,7 +40,7 @@ pub(crate) fn try_from_u32(s: Structure<'_>) -> TokenStream {
         use ::core::primitive::u32;
         use ::core::result::Result::{self, Ok, Err};
 
-        r#gen impl TryFrom<u32> for @Self {
+        gen impl TryFrom<u32> for @Self {
             type Error = u32;
 
             #[allow(deprecated)] // Don't warn about deprecated variants.

src/ci/github-actions/jobs.yml

@@ -102,6 +102,8 @@ pr:
     <<: *job-linux-16c
   - image: x86_64-gnu-tools
     <<: *job-linux-16c
+  - image: x86_64-gnu
+    <<: *job-linux-4c
 
 # Jobs that run when you perform a try build (@bors try)
 # These jobs automatically inherit envs.try, to avoid repeating