JDK 16 RFR of JDK-8250920: Increase @jls usage in core reflection

[Joe Darcy]

Hello,

While JDK-8250660: "Clarify that WildcardType and AnnotatedWildcardType 
bounds methods return one" is still under discussion, please review a 
change for

    JDK-8250920: Increase @jls usage in core reflection
    http://cr.openjdk.java.net/~darcy/8250920.0/

which adds @jls tags for the type-modeling components of the 
java.lang.reflect package.

Thanks,

-Joe