Add a CI job.

Author: ZeroIntensity

.github/workflows/build.yml

@@ -142,6 +142,10 @@ jobs:
       - name: Check for unsupported C global variables
         if: github.event_name == 'pull_request'  # $GITHUB_EVENT_NAME
         run: make check-c-globals
+      - name: Check for undocumented C APIs
+        if: github.event_name == 'pull_request'
+        run: make check-c-api-docs
+
 
   build-windows:
     name: >-

Makefile.pre.in

@@ -3313,6 +3313,11 @@ check-c-globals:
 		--format summary \
 		--traceback
 
+# Check for undocumented C APIs.
+.PHONY: check-c-globals
+check-c-api-docs:
+	$(PYTHON_FOR_REGEN) $(srcdir)/Tools/check-c-api-docs/main.py
+
 # Find files with funny names
 .PHONY: funny
 funny: