merge revision(s) 39492: [Backport #6807]

	* common.mk (realclean-local): miniprelude.c is made by srcs, so it
	  should not removed by distclean but by realclean.  [Bug #6807]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39705 b2dd03c8-39d4-4d8f-98ff-823fe69b080e