[9] RFR (S): 8050887: Intrinsify constants for default values

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8050887/webrev.00
https://bugs.openjdk.java.net/browse/JDK-8050887

Intrinsify MethodHandles.constant() for default values.

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

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

Thanks!

Best regards,
Vladimir Ivanov