[bazel] port 3bdfa6f

Author: slackito

utils/bazel/llvm-project-overlay/clang-tools-extra/unittests/BUILD.bazel

@@ -70,6 +70,8 @@ cc_test(
         "//clang-tools-extra/clang-doc:lib",
         "//llvm:BitstreamReader",
         "//llvm:BitstreamWriter",
+        "//llvm:TestingSupport",
+        "//third-party/unittest:gmock",
         "//third-party/unittest:gtest",
         "//third-party/unittest:gtest_main",
     ],