run-tests: move createhgrc() call into Test.run()
createhgrc() is an implementation detail of how tests are run. It makes
sense to move it into Test.run().
Note that this will cause the test execution time to include the
creation of hgrc. The author does not believe this is a significant
change worth worrying about.
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ ls
a
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
B should disappear
$ ls
a