RFR: JDK-8243057: compilation of annotated static record fields fails with NPE

[Vicente Romero]

Please review fix for [1] at [2]. At method Check::validateAnnotation 
the condition used to determine if a field is or not a record field was 
wrong. As a consequence static fields were considered as record fields. 
This doesn't have any consequence unless they are annotated. This patch 
is fixing this issue.

Thanks,
Vicente

[1] https://bugs.openjdk.java.net/browse/JDK-8243057
[2] http://cr.openjdk.java.net/~vromero/8243057/webrev.00/