[14] RFR(S): 8226879: Memory leak in Type::hashcons

[Tobias Hartmann]

Hi,

please review the following patch:
https://bugs.openjdk.java.net/browse/JDK-8226879
http://cr.openjdk.java.net/~thartmann/8226879/webrev.00/

We might allocate a new type in xdual() but if the type is self symmetric we just discard it without
calling delete. This only affects the per-compilation arena (which is freed after compilation).

Thanks,
Tobias