Problem-reporting capable compilation doesn't emit error count

[hegyibalint]

Current behavior (after #28281)

The error count is missing when compilation problems happen:

gradle/platforms/documentation/docs/src/snippets/java-library/module-disabled/tests/buildJavaModule.out

Line 10 in 30662f2

2 errors

Expected behavior

The error counter is to be present.

Context

As part of #28281, we took charge of Java compilation error reporting.
We believe this breakage is acceptable as the value is trivial to compute (number of errors in the console) or straight out omitted by command line parsers.

Nevertheless, this issue documents this change available for any community feedback.