JDK 14 RFR of JDK-8230626: Make UnknownFooException strings more informative

[mark.reinhold at oracle.com]

2019/9/4 14:19:00 -0700, joe.darcy at oracle.com:
> Responding to some off-list input from Jon, please review the small 
> enhancement for
> 
>   JDK-8230626: Make UnknownFooException strings more informative
>   http://cr.openjdk.java.net/~darcy/8230626.0/
> 
> Patch below; thanks,

> ...
> - super("Unknown annotation value: " + av);
> + super("Unknown annotation value: ``" + av + "''");

The use of GNU-style ``fake curly quotes'' in JDK messages is extremely
rare, and jarring to the eye in most typefaces.  Pairs of backticks and
apostrophes are a poorer subsitute for “true curly quotes” than simple
"vertical quotation marks."  Please use vertical quotation marks, which
is what we use pretty much everywhere.

- Mark