RFR : JDK-8202832: cycle detection depends on ordering of requires directives

[Jan Lahoda]

Hi,

Detection of cyclic dependency among modules is broken, as the tested 
module is marked as acyclic after checking its first dependency.

The intent of marking the module acyclic was to prevent duplicated 
errors, but it might be more consistent to report error on all sources 
that are included in the cycle, so this is what the proposed patch is doing.

Webrev:
http://cr.openjdk.java.net/~jlahoda/8202832/webrev.00/

Bug:
https://bugs.openjdk.java.net/browse/JDK-8202832

Thanks,
     Jan