Support rescuing foreign exceptions

[eregon]

Reported by @jylamont in https://graalvm.slack.com/archives/CMY63522F/p1637250173107100

Like rescue Java.type('org.foo.SomeException').

rescue Java.type('org.postgresql.util.PSQLException') should work but it does not currently.

---

It's unclear if a lone rescue should rescue foreign exceptions.

JRuby behavior seems to treat StandardError specially as an ad-hoc way to support lone rescue.
I am not sure we want to follow that.

~ ∴ ruby -e 'begin; p java.lang.Integer.valueOf("abc"); rescue => e; p e; p e.class; p e.class.ancestors; end'          
java.lang.NumberFormatException: For input string: "abc"
Java::JavaLang::NumberFormatException
[Java::JavaLang::NumberFormatException, Java::JavaLang::IllegalArgumentException, Java::JavaLang::RuntimeException, Java::JavaLang::Exception, Java::JavaLang::Throwable, Java::JavaIo::Serializable, Java::JavaLang::Object, ConcreteJavaProxy, JavaProxy, JavaProxyMethods, Object, Kernel, BasicObject]

~ ∴ ruby -e 'begin; p java.lang.Integer.valueOf("abc"); rescue RuntimeError => e; p e; p e.class; p e.class.ancestors; end' 
Unhandled Java exception: java.lang.NumberFormatException: For input string: "abc"
java.lang.NumberFormatException: For input string: "abc"
                     forInputString at java/lang/NumberFormatException.java:65
                           parseInt at java/lang/Integer.java:652
                            valueOf at java/lang/Integer.java:983
                            invoke0 at jdk/internal/reflect/NativeMethodAccessorImpl.java:-2
                             invoke at jdk/internal/reflect/NativeMethodAccessorImpl.java:62
                             invoke at jdk/internal/reflect/DelegatingMethodAccessorImpl.java:43
                             invoke at java/lang/reflect/Method.java:566
  invokeDirectWithExceptionHandling at org/jruby/javasupport/JavaMethod.java:456
                 invokeStaticDirect at org/jruby/javasupport/JavaMethod.java:368
               invokeOther3:valueOf at -e:1
                             <main> at -e:1
                                run at -e:-1
                invokeWithArguments at java/lang/invoke/MethodHandle.java:710
                          runScript at org/jruby/Ruby.java:1257
                        runNormally at org/jruby/Ruby.java:1176
                        runNormally at org/jruby/Ruby.java:1158
                        runNormally at org/jruby/Ruby.java:1194
                        runFromMain at org/jruby/Ruby.java:977
                      doRunFromMain at org/jruby/Main.java:400
                        internalRun at org/jruby/Main.java:292
                                run at org/jruby/Main.java:234
                               main at org/jruby/Main.java:206

~ ∴ ruby -e 'begin; p java.lang.Integer.valueOf("abc"); rescue StandardError => e; p e; p e.class; p e.class.ancestors; end'
java.lang.NumberFormatException: For input string: "abc"
Java::JavaLang::NumberFormatException
[Java::JavaLang::NumberFormatException, Java::JavaLang::IllegalArgumentException, Java::JavaLang::RuntimeException, Java::JavaLang::Exception, Java::JavaLang::Throwable, Java::JavaIo::Serializable, Java::JavaLang::Object, ConcreteJavaProxy, JavaProxy, JavaProxyMethods, Object, Kernel, BasicObject]

~ ∴ ruby -e 'begin; p java.lang.Integer.valueOf("abc"); rescue Exception => e; p e; p e.class; p e.class.ancestors; end'
java.lang.NumberFormatException: For input string: "abc"
Java::JavaLang::NumberFormatException
[Java::JavaLang::NumberFormatException, Java::JavaLang::IllegalArgumentException, Java::JavaLang::RuntimeException, Java::JavaLang::Exception, Java::JavaLang::Throwable, Java::JavaIo::Serializable, Java::JavaLang::Object, ConcreteJavaProxy, JavaProxy, JavaProxyMethods, Object, Kernel, BasicObject]

So all host exceptions seem to be considered StandardError or so, even though the ancestors do not reflect that.
https://github.com/jruby/jruby/wiki/CallingJavaFromJRuby#exception-handling

Internal issue: GR-34933

[eregon]

This is now implemented: e6753ad

[jylamont]

Thanks for this @eregon!