Add load() statements to TARGETS files

Reviewed By: luciang

Differential Revision: D13733578

fbshipit-source-id: 556c115935aa42c1da85ec0e91199b9f198fc467

TARGETS

 load("@fbcode_macros//build_defs:auto_headers.bzl", "AutoHeaders")
+load("@fbcode_macros//build_defs:cpp_library.bzl", "cpp_library")
 load(":defs.bzl", "test_binary")
 
 REPO_PATH = package_name() + "/"