tests: add test for unqualified include of a built-in template map
The feature was added in
081b08e4ea13 (templater: look for mapfiles in
template paths, 2015-05-15), but no test case was added.
Differential Revision: https://phab.mercurial-scm.org/D8797
public attribute not declared in interfaces: badpeer.badattribute
public attribute not declared in interfaces: badpeer.badmethod