gpu-compute,tests: Move GPU tests to testlib (#1270)

A new host tag `gcn_gpu` has been added. This allows for selection of
those GPU tests which depend upon the gcn-gpu docker image to run.

In addition to this, the square GPU tests has been moved to the CI
tests. This ensures some GPU code is compiled and run on every PR.

.github/workflows/ci-tests.yaml

@@ -221,6 +221,32 @@ jobs:
                   path: tests/testing-results
                   retention-days: 30
 
+    gpu-tests:
+        runs-on: [self-hosted, linux, x64]
+        container: ghcr.io/gem5/gcn-gpu:latest
+        timeout-minutes: 180
+        needs: [pre-commit, check-for-change-id]
+        steps:
+            - uses: actions/checkout@v4
+
+            # Build the VEGA_X86/gem5.opt binary.
+            - name: Build VEGA_X86/gem5.opt
+              run: scons build/VEGA_X86/gem5.opt -j`nproc`
+
+            # Run the GPU tests.
+            - name: Run Testlib GPU Tests
+              working-directory: ${{ github.workspace }}/tests
+              run: ./main.py run  --skip-build -vvv -t $(nproc) --host gcn_gpu gem5/gpu
+
+            # Upload the tests/testing-results directory as an artifact.
+            - name: Upload results
+              if: success() || failure()
+              uses: actions/upload-artifact@v4
+              with:
+                  name: ci-tests-run-${{ github.run_number }}-attempt-${{ github.run_attempt }}-gpu-status-${{ steps.run-tests.outcome }}-output
+                  path: tests/testing-results
+                  retention-days: 30
+
     ci-tests:
     # It is 'testlib-quick' which needs to pass for the pull request to be
     # merged. This job is a dummy job that depends on all the other jobs.
@@ -232,5 +258,6 @@ jobs:
             - unittests-all-opt
             - pre-commit
             - check-for-change-id
+            - gpu-tests
         steps:
             - run: echo "This job's status is ${{ job.status }}."