tmp: enable llvm-18 builder on PRs

Author: lqd

.github/workflows/ci.yml

@@ -62,6 +62,10 @@ jobs:
             env:
               ENABLE_GCC_CODEGEN: "1"
             os: ubuntu-20.04-16core-64gb
+          - name: x86_64-gnu-llvm-18
+            env:
+              RUST_BACKTRACE: 1
+            os: ubuntu-20.04-8core-32gb
           - name: x86_64-gnu-tools
             os: ubuntu-20.04-16core-64gb
             env: {}

src/ci/github-actions/ci.yml

@@ -363,6 +363,11 @@ jobs:
               ENABLE_GCC_CODEGEN: "1"
             <<: *job-linux-16c
 
+          - name: x86_64-gnu-llvm-18
+            env:
+              RUST_BACKTRACE: 1
+            <<: *job-linux-8c
+
           - name: x86_64-gnu-tools
             <<: *job-linux-16c