auto merge of #4814 : brson/rust/check, r=nikomatsakis

r? @nikomatsakis The third commit here is the one that makes the test suite remember which steps have completed successfully.

configure

@@ -624,7 +624,7 @@ do
     make_dir $h/test/doc-tutorial-macros
     make_dir $h/test/doc-tutorial-borrowed-ptr
     make_dir $h/test/doc-tutorial-tasks
-    make_dir $h/test/doc-ref
+    make_dir $h/test/doc-rust
 done
 
 # Configure submodules

mk/clean.mk

@@ -48,7 +48,7 @@ clean-misc:
 	$(Q)rm -f $(RUSTLLVM_LIB_OBJS) $(RUSTLLVM_OBJS_OBJS) $(RUSTLLVM_DEF)
 	$(Q)rm -Rf $(DOCS)
 	$(Q)rm -Rf $(GENERATED)
-	$(Q)rm -f tmp/*.log tmp/*.rc tmp/*.rs
+	$(Q)rm -f tmp/*.log tmp/*.rc tmp/*.rs tmp/*.ok
 	$(Q)rm -Rf rust-stage0-*.tar.bz2 $(PKG_NAME)-*.tar.gz dist
 	$(Q)rm -Rf $(foreach ext, \
                  html aux cp fn ky log pdf pg toc tp vr cps, \