hg: panama/dev: 8232907: NPE in FunctionDescriptor::hashCode for function without return type (void)

[henry.jen at oracle.com]

Changeset: 77318798aae6
Author:    henryjen
Date:      2019-10-23 09:49 -0700
URL:       https://hg.openjdk.java.net/panama/dev/rev/77318798aae6

8232907: NPE in FunctionDescriptor::hashCode for function without return type (void)
Reviewed-by: mcimadamore

! src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/FunctionDescriptor.java