merge revision(s) 39209:

	Get libc's path by ldd [Bug #7828] [ruby-core:52129]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39216 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 39210:

	Suppress warnings: setting Encoding.default_external

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39217 b2dd03c8-39d4-4d8f-98ff-823fe69b080e