Rollup merge of rust-lang#57010 - phansch:run_compiletest_tests_on_ci, r=kennytm

Actually run compiletest tests on CI

I was assuming that rust-lang#56792 would
have resulted in compiletest tests being executed on CI. However, I
couldn't find any mentions of the unit test names in any CI logs.

This adds the compiletest test execution to the checktools.sh script.

Author: Centril

src/ci/docker/mingw-check/Dockerfile

@@ -21,4 +21,5 @@ RUN sh /scripts/sccache.sh
 
 ENV RUN_CHECK_WITH_PARALLEL_QUERIES 1
 ENV SCRIPT python2.7 ../x.py check --target=i686-pc-windows-gnu --host=i686-pc-windows-gnu && \
-           python2.7 ../x.py build --stage 0 src/tools/build-manifest
+           python2.7 ../x.py build --stage 0 src/tools/build-manifest && \
+           python2.7 ../x.py test --stage 0 src/tools/compiletest