[libc++] Add GCC12 CI job

[philnik]

• Fix CI

[philnik]

• Disable format tests and enable implicit_deduction_guides.pass.cpp for GCC 12

[ldionne]

libcxx/utils/ci/run-buildbot

302–303

We should actually switch to GCC 12 instead of adding a new job. We only support the latest-released GCC per our policy. We should also update https://libcxx.llvm.org/#platform-and-compiler-support to say that we support GCC 12 only.

[philnik]

libcxx/utils/ci/run-buildbot

302–303

Wouldn't that mean that we only support clang 14 and 15? I thought the logic was "the latest compiler at the time of the last release branch".

[Mordante]

@philnik I'm a bit puzzled by this review. How does this differ from D126667?

[philnik]

In D127618#3578614, @Mordante wrote:

@philnik I'm a bit puzzled by this review. How does this differ from D126667?

Sorry, I completely forgot that you already worked on that.

[Mordante]

No problem, I just was a bit confused; I thought these were comments to my patch ;-)

libcxx/utils/ci/buildkite-pipeline.yml

agents:
       os: "linux"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
   # Tests with the supported compilers.
+  - group: "Supported compilers"
+    steps:
     - label: "GCC 11 / C++11"
       command: "libcxx/utils/ci/run-buildbot generic-gcc-cxx11"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
+    - label: "GCC 12"
+      command: "libcxx/utils/ci/run-buildbot generic-gcc12"
+      artifact_paths:
+        - "**/test-results.xml"
+        - "**/*.abilist"
+      agents:
+        queue: "libcxx-builders"
+        os: "linux"
+      retry:
+        automatic:
+          - exit_status: -1  # Agent was lost
+            limit: 2
+      timeout_in_minutes: 120
+
     - label: "Clang 13"
       command: "libcxx/utils/ci/run-buildbot generic-clang-13"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
     - label: "Clang 14"
       command: "libcxx/utils/ci/run-buildbot generic-clang-14"
       artifact_paths:
         - "**/test-results.xml"
         - "**/*.abilist"
       agents:
         queue: "libcxx-builders"
         os: "linux"
       retry:
         automatic:
           - exit_status: -1  # Agent was lost
             limit: 2
       timeout_in_minutes: 120
 
   # Tests with the sanitizers.
   - group: "Sanitizers"
     steps:
     - label: "ASAN"
       command: "libcxx/utils/ci/run-buildbot generic-asan"
       artifact_paths:
         - "**/test-results.xml"

libcxx/utils/ci/run-buildbot

generic-gcc)
     export CC=gcc-11
     export CXX=g++-11
     clean
     generate-cmake -DLIBCXX_ENABLE_WERROR=NO \
                    -DLIBCXXABI_ENABLE_WERROR=NO \
                    -DLIBUNWIND_ENABLE_WERROR=NO
     check-runtimes
 ;;
+generic-gcc)
+    export CC=gcc-12
+    export CXX=g++-12
+    clean
+    generate-cmake -DLIBCXX_ENABLE_WERROR=NO \
+                   -DLIBCXXABI_ENABLE_WERROR=NO \
+                   -DLIBUNWIND_ENABLE_WERROR=NO
+    check-runtimes
+;;
 generic-gcc-cxx11)
     export CC=gcc-11
     export CXX=g++-11
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx11.cmake" \
                    -DLIBCXX_ENABLE_WERROR=NO \
                    -DLIBCXXABI_ENABLE_WERROR=NO \
                    -DLIBUNWIND_ENABLE_WERROR=NO
     check-runtimes
 ;;
 generic-asan)