ART: Clean up utils.h

Remove functionality provided by libbase. Move some single-use
functions to their respective users.

Test: m test-art-host
Change-Id: I75594035fa975200d638cc29bb9f31bc6e6cb29f
diff --git a/oatdump/oatdump_test.cc b/oatdump/oatdump_test.cc
index 22db818..a2eba45 100644
--- a/oatdump/oatdump_test.cc
+++ b/oatdump/oatdump_test.cc
@@ -18,6 +18,8 @@
 #include <string>
 #include <vector>
 
+#include "android-base/strings.h"
+
 #include "common_runtime_test.h"
 
 #include "base/stringprintf.h"
@@ -143,7 +145,7 @@
       }
       argv.push_back(nullptr);
       UNUSED(execv(argv[0], &argv[0]));
-      const std::string command_line(Join(exec_argv, ' '));
+      const std::string command_line(android::base::Join(exec_argv, ' '));
       PLOG(ERROR) << "Failed to execv(" << command_line << ")";
       // _exit to avoid atexit handlers in child.
       _exit(1);