adds benchmark tool

pirms 3 gadiem · 06d4e77b1b
--- a/.gitmodules
+++ b/.gitmodules
@@ -4,3 +4,6 @@
 [submodule "3rd/gtest"]
 	path = 3rd/gtest
 	url = https://github.com/google/googletest.git
 [submodule "3rd/gbench"]
 	path = 3rd/gbench
 	url = git@github.com:henrydcase/benchmark.git
--- a/3rd/gbench
+++ b/3rd/gbench
@@ -0,0 +1 @@
 Subproject commit e45fcc64e02489f718df499a162b41f742a1b7e5