Run codegen tests outside if not llvm-15

.github/workflows/ci.yml

@@ -57,8 +57,9 @@ jobs:
             os: ubuntu-20.04-4core-16gb
             env: {}
           - name: x86_64-gnu-llvm-15
+            env:
+              SKIP_CODEGEN_TESTS: "1"
             os: ubuntu-20.04-16core-64gb
-            env: {}
           - name: x86_64-gnu-tools
             os: ubuntu-20.04-16core-64gb
             env: {}

src/ci/docker/host-x86_64/x86_64-gnu-llvm-15/script.sh

@@ -4,7 +4,11 @@ set -ex
 
 # Only run the stage 1 tests on merges, not on PR CI jobs.
 if [[ -z "${PR_CI_JOB}" ]]; then
+    if [[ "${SKIP_CODEGEN_TESTS}" == "1" ]]; then
         ../x.py --stage 1 test --skip src/tools/tidy --skip tests/codegen
+    else
+        ../x.py --stage 1 test --skip src/tools/tidy
+    fi
 
     # Run the `mir-opt` tests again but this time for a 32-bit target.
     # This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
@@ -20,7 +24,11 @@ if [[ -z "${PR_CI_JOB}" ]]; then
 fi
 
 # NOTE: intentionally uses all of `x.py`, `x`, and `x.ps1` to make sure they all work on Linux.
+if [[ "${SKIP_CODEGEN_TESTS}" == "1" ]]; then
     ../x.py --stage 2 test --skip src/tools/tidy --skip tests/codegen
+else
+    ../x.py --stage 2 test --skip src/tools/tidy
+fi
 
 # Run the `mir-opt` tests again but this time for a 32-bit target.
 # This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have

src/ci/docker/run.sh

@@ -271,6 +271,7 @@ docker \
   run \
   --workdir /checkout/obj \
   --env SRC=/checkout \
+  --env "SKIP_CODEGEN_TESTS=$SKIP_CODEGEN_TESTS" \
   $args \
   --env CARGO_HOME=/cargo \
   --env DEPLOY \

src/ci/github-actions/ci.yml

@@ -332,6 +332,8 @@ jobs:
 
           - name: x86_64-gnu-llvm-15
             <<: *job-linux-16c
+            env:
+              SKIP_CODEGEN_TESTS: "1"
 
           - name: x86_64-gnu-tools
             <<: *job-linux-16c