Javadoc may not log all errors

[raboof]

When debugging an instance where javadoc produced the error "javadoc: error - invalid flag: -target", this error was not printed on javacLogger.flush(exitCode).

It was correctly added to JavacLogger.msgs with level error, so I'd expect parseAndDumpSemanticErrors to fail to parse it and log it instead, not sure why that doesn't appear to be happening.

[jvican]

@raboof Any ideas how we can reproduce/test this?

[raboof]

Like raboof@6253cee ?

[jvican]

That looks good. Hopefully we fix this soon. Thanks @raboof! 😄

[jvican]

Closing in favor of #520 which is richer in details. We'll add the provided reproduced case in this ticket to our test suite, thank you @raboof