bpo-42545: Check that all symbols in the limited ABI are exported (GH-23616)

Author: pablogsal

.github/workflows/build.yml

@@ -75,6 +75,8 @@ jobs:
           fi
       - name: Check exported libpython symbols
         run: make smelly
+      - name: Check limited ABI symbols
+        run: make check-limited-abi
 
   build_win32:
     name: 'Windows (x86)'

.travis.yml

@@ -192,6 +192,8 @@ script:
   - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then ./python Tools/scripts/patchcheck.py --travis $TRAVIS_PULL_REQUEST; fi
   # Check that all symbols exported by libpython start with "Py" or "_Py"
   - make smelly
+  # Check that all symbols in the limited abi are present
+  - make check-limited-abi
   # `-r -w` implicitly provided through `make buildbottest`.
   - |
     if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then