Fix outdated src/test/mb/ tests, and add a GB18030 test.

Tom Lane <tgl@sss.pgh.pa.us>

Commit: 07af523870bcfe930134054febd3a6a114942e5b
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: 2015-05-15T17:47:42Z
Releases: 9.5.0
Fix outdated src/test/mb/ tests, and add a GB18030 test.

The expected-output files for these tests were broken by the recent
addition of a warning for hash indexes.  Update them.

Also add a test case for GB18030 encoding, similar to the other ones.
This is a pretty weak test, but it's better than nothing.

Files