Ruby » Ruby master

configure.in: check lgamma_r(-0.0)

• configure.in (rb_cv_lgamma_r_m0): check if lgamma_r(-0.0)
  returns negative infinity. [Bug #12249]
• math.c (ruby_lgamma_r): define by the configured result.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54499 b2dd03c8-39d4-4d8f-98ff-823fe69b080e