Only test std, alloc and core

Author: diondokter

src/ci/docker/scripts/x86_64-gnu-llvm.sh

@@ -9,12 +9,12 @@ if [[ -z "${PR_CI_JOB}" ]]; then
     # The tests are run a second time with the size optimizations enabled.
     if [[ "${ENABLE_GCC_CODEGEN}" == "1" ]]; then
         ../x.py --stage 1 test --skip src/tools/tidy --skip tests/codegen
-        ../x.py --stage 1 test --skip src/tools/tidy --skip tests/codegen \
+        ../x.py --stage 1 test library/std library/alloc library/core \
             --rustc-args "--cfg feature=\"optimize_for_size\""
     else
         ../x.py --stage 1 test --skip src/tools/tidy
-        ../x.py --stage 1 test --skip src/tools/tidy --rustc-args \
-            "--cfg feature=\"optimize_for_size\""
+        ../x.py --stage 1 test library/std library/alloc library/core \
+            --rustc-args "--cfg feature=\"optimize_for_size\""
     fi
 
     # Run the `mir-opt` tests again but this time for a 32-bit target.