RFR (javac) 8029558: VerifyError: Bad return type when lambda's body is in parentheses

[Robert Field]

Please review compiler (javac) fix for:

https://bugs.openjdk.java.net/browse/JDK-8029558

Webrev:

http://cr.openjdk.java.net/~rfield/8029558v0/ 
<http://cr.openjdk.java.net/%7Erfield/8029558v0/>

Fix is to correctly treat the lambda body as a value returning entity 
rather than a void entity so that that the correct type converting casts 
are generated.  This is done by passing the erased type rather than null 
as the expected type.

Thanks,
Robert