RFR 8233920: MethodHandles::tryFinally generates illegal bytecode for long/double return types

[Jorn Vernee]

Hi,

Please review the following patch that fixes handling of long/double 
returns for the tryFinally MethodHandle combinator.

Bug: https://bugs.openjdk.java.net/browse/JDK-8233920
Webrev: http://cr.openjdk.java.net/~jvernee/8233920/webrev.01/
(Testing=tier1)

FWIW, I also added some missing close tags to the javadoc in the 
InvokerBytecodeGenerator class (IntelliJ was warning about this).

As a heads-up; I'm not a committer on the jdk project, so a sponsor 
would be needed to push this.

Thanks,
Jorn