hg: lambda/lambda/jdk: Update initial lambda APIs and tests to use new syntax.

[Bob Foster]

Remi Forax wrote:

> BTW I think the methods xor should be removed
>  for the same reason there is no ^^ in C
>  (nobody use xor in test between booleans)

There is no ^^ in C because xor can't be short-circuited. You can, however,
use ^ to combine logical results in C. I've done it.

Pedantry aside, you're probably right. :)

Bob