RFR: JDK-8236692: static final fields without initializer are accepted by javac

[Vicente Romero]

Please review the fix for [1] at [2], javac was failing to issue an 
error for code like:

record R() {
     public static final int X;
}

even though `X` was not initialized as the automatic code to generate 
initializer expressions only apply to the fields generated from the 
record component. The patch updates the code in Flow that analyzes 
compact constructors to don't bail out if the variable being analyzed is 
static.

Thanks,
Vicente

[1] https://bugs.openjdk.java.net/browse/JDK-8236692
[2] http://cr.openjdk.java.net/~vromero/8236692/webrev.00/