Do x check on various bootstrap tools in CI

Author: Zalathar

src/ci/docker/host-x86_64/pr-check-2/Dockerfile

@@ -28,7 +28,10 @@ RUN sh /scripts/sccache.sh
 
 ENV SCRIPT \
         python3 ../x.py check && \
-        python3 ../x.py check src/tools/bump-stage0 && \
+        # Check some tools that aren't included in `x check` by default, to
+        # ensure that maintainers can still do check builds locally.
+        python3 ../x.py check bootstrap bump-stage0 compiletest coverage-dump \
+          linkchecker run-make-support rustdoc-gui-test && \
         python3 ../x.py clippy ci --stage 2 && \
         python3 ../x.py test --stage 1 core alloc std test proc_macro && \
         python3 ../x.py test --stage 1 src/tools/compiletest && \