[9] RFR (L): Improve LambdaForm sharing by using LambdaFormEditor more extensively

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8057922/webrev.00
https://bugs.openjdk.java.net/browse/JDK-8057922

Introduce more sharing on LambdaForm level by rewriting most of the MH 
combinators using LambdaFormEditor.

The new code is guarded by USE_LAMBDA_FORM_EDITOR flag and turned off by 
default because it introduces significant peak performance regression on 
Octane benchmark. I'm working on the fix. Original implementation will 
be removed once performance degradation is fixed.

Testing: jdk/java/lang/invoke, jdk/java/util/streams, nashorn, octane w/ 
"-ea -esa", COMPILE_THRESHOLD={0,30}, and 
USE_LAMBDA_FORM_EDITOR={true,false}.

Reviewed-by: vlivanov, ?
Contributed-by: john.r.rose at oracle.com

Thanks!

Best regards,
Vladimir Ivanov