* win32/mkexports.rb (each_export): skip garbages generated by VS2012's
	  nmake.
	  reported and patched by Yoshida Masato at [Bug #7333] [ruby-dev:46484]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@38320 b2dd03c8-39d4-4d8f-98ff-823fe69b080e