Admit defeat on the prospect of keeping straight exactly which platforms

Admit defeat on the prospect of keeping straight exactly which platforms
produce which output in the geometry test, even with the problem narrowed
down to only whether they print minus zero or not.  Instead, use
pg_regress' locale-variant mechanism to automatically consider the test
to pass if it matches either supplied comparison file.  geometry_1.out
replaces the former geometry-positive-zeros.out.