precision treatment errors.
* test/bigdecimal/test_bigdecimal.rb: add tests for the above change.
fix precision treatment errors.
* ext/bigdecimal/bigdecimal.c (BigDecimal_power): precision argument
should be optional for its compatibility.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32500 b2dd03c8-39d4-4d8f-98ff-823fe69b080e