Searching for the single abstract method leads to computing
whole member scopes of given intrefaces, especially when
they contain a lot of methods (i.e. they're definitely not SAMs)
On the other side this method is very hot because it's called
for each Java interface used as a type for some value parameter
(for building SAM adapters)
The idea is to apply some heuristics to understand using only
JavaMethod and supertypes that this interface is definitely not a SAM
Denis Zharkov
e4cb5496b8