In AlterRole, make bypassrls an int

In AlterRole, make bypassrls an int

When reworking bypassrls in AlterRole to operate the same way the other
attribute handling is done, I missed that the variable was incorrectly a
bool rather than an int.  This meant that on platforms with an unsigned
char, we could end up with incorrect behavior during ALTER ROLE.

Pointed out by Andres thanks to tests he did changing our bool to be the
one from stdbool.h which showed this and a number of other issues.

Add regression tests to test CREATE/ALTER role for the various role
attributes.  Arrange to leave roles behind for testing pg_dumpall, but
none which have the LOGIN attribute.

Back-patch to 9.5 where the AlterRole bug exists.