Ruby » Ruby master

merge revision(s) 38801,38809,38810: [Backport #7404]

    * ext/bigdecimal/bigdecimal.c (BigDecimal_sub):
      need to specify precision for converting Rational and Float.
      [ruby-dev:46544] [Bug #7404]

    * ext/bigdecimal/bigdecimal.c (BigDecimal_mult): ditto.

    * ext/bigdecimal/bigdecimal.c (BigDecimal_divide): ditto.

    * ext/bigdecimal/bigdecimal.c (BigDecimal_DoDivmod): ditto.

    * ext/bigdecimal/bigdecimal.c (BigDecimal_divremain): ditto.

    * test/bigdecimal/test_bigdecimal.rb: add tests for the above fixes.

    * ext/bigdecimal/bigdecimal.c: use `RB_TYPE_P(x, t)` instead of
      `TYPE(x) == t`.

    * ext/bigdecimal/bigdecimal.c (BigDecimal_to_s): use CRuby style.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@38829 b2dd03c8-39d4-4d8f-98ff-823fe69b080e