Add 'bench' target to makefiles.

R=rsc, agl, r
CC=golang-dev
https://golang.org/cl/188043
diff --git a/src/Make.pkg b/src/Make.pkg
index d4196b6..3dd57b7 100644
--- a/src/Make.pkg
+++ b/src/Make.pkg
@@ -53,6 +53,9 @@
 test:
 	$(QUOTED_GOBIN)/gotest
 
+bench:
+	$(QUOTED_GOBIN)/gotest -benchmarks=. -match="Do not run tests"
+
 nuke: clean
 	rm -f $(pkgdir)/$(TARG).a
 
diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index 0caa0dd..4f001db 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -134,13 +134,20 @@
 	testing/iotest\
 	xgb\
 
+NOBENCH=\
+	container/vector\
+
 TEST=\
 	$(filter-out $(NOTEST),$(DIRS))
 
+BENCH=\
+	$(filter-out $(NOBENCH),$(TEST))
+
 clean.dirs: $(addsuffix .clean, $(DIRS))
 install.dirs: $(addsuffix .install, $(DIRS))
 nuke.dirs: $(addsuffix .nuke, $(DIRS))
 test.dirs: $(addsuffix .test, $(TEST))
+bench.dirs: $(addsuffix .bench, $(BENCH))
 
 %.clean:
 	+cd $* && $(QUOTED_GOBIN)/gomake clean
@@ -154,12 +161,17 @@
 %.test:
 	+cd $* && $(QUOTED_GOBIN)/gomake test
 
+%.bench:
+	+cd $* && $(QUOTED_GOBIN)/gomake bench
+
 clean: clean.dirs
 
 install: install.dirs
 
 test:	test.dirs
 
+bench:	bench.dirs
+
 nuke: nuke.dirs
 	rm -rf "$(GOROOT)"/pkg/*