merge revision(s) r44505: [Backport #9994]

	numeric.c: isfinite

	* numeric.c (flo_is_finite_p): prefer C99 standard isfinite() than
  deprecated finite().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@46610 b2dd03c8-39d4-4d8f-98ff-823fe69b080e