Ruby

common.mk: more clean

• common.mk (distclean-local): remove autom4te.cache generated by
  autoconf.
• common.mk (realclean-local): remove id sources and dummy header
  for dtrace. [ruby-core:67562] [Bug #10737]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49237 b2dd03c8-39d4-4d8f-98ff-823fe69b080e