Turn on make check-rust

This will turn on the test-suite which does have a currently failing test
lets see what happens the workflow in github.

Author: philberty

.github/workflows/ccpp.yml

@@ -43,4 +43,5 @@ jobs:
     - name: Build
       run: |
            cd gccrs-build; \
-           make
+           make; \
+           make check-rust