Summary

Update javac's implementation of ExecutableType.getReceiverType() to return NONE rather than null if a receiver type is not defined.

Problem

The implementation of ExecutableType.getReceiverType() in javac does not obey the specification in cases where the receiver type is not explicitly set.

Solution

Update the implementation. The analogous change for ExecutableElement.getReceiverType() was made under JDK-8222369.

Specification

No specification update; behavior change only.