adds gtest

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "test/pycparser"]
 	path = test/pycparser
 	url = https://github.com/eliben/pycparser.git
+[submodule "3rd/gtest"]
+	path = 3rd/gtest
+	url = https://github.com/google/googletest.git

3rd/gtest

@@ -0,0 +1 @@
+Subproject commit 1a8ecf1813d022cc7914e04564b92decff6161fc

CMakeLists.txt

@@ -33,6 +33,8 @@ else()
   message(FATAL_ERROR "Unknown processor:" ${CMAKE_SYSTEM_PROCESSOR})
 endif()
 
+add_subdirectory(3rd/gtest)
+
 # Arch settings
 
 if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")