* object.c (rb_obj_ivar_set): call to_str for string only once.

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* 2013-04-08

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40179 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Suppress warnings

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40180 b2dd03c8-39d4-4d8f-98ff-823fe69b080e