Reland D38460202 and fix tests

Summary: Reland D38460202 (e874e5f) and fix test errors.

Reviewed By: RSNara

Differential Revision: D38846070

fbshipit-source-id: 05a889aabe7e25225ff7464f69900c459c82dd47

ReactCommon/react/renderer/mapbuffer/BUCK

@@ -1,6 +1,8 @@
 load(
     "//tools/build_defs/oss:rn_defs.bzl",
     "ANDROID",
+    "APPLE",
+    "CXX",
     "fb_xplat_cxx_test",
     "get_apple_compiler_flags",
     "get_apple_inspector_flags",
@@ -38,7 +40,7 @@ rn_xplat_cxx_library(
         "supermodule:xplat/default/public.react_native.infra",
     ],
     macosx_tests_override = [],
-    platforms = ANDROID,
+    platforms = (ANDROID, APPLE, CXX),
     preprocessor_flags = [
         "-DLOG_TAG=\"ReactNative\"",
         "-DWITH_FBSYSTRACE=1",
@@ -63,7 +65,7 @@ fb_xplat_cxx_test(
         "-Wall",
     ],
     contacts = ["oncall+react_native@xmail.facebook.com"],
-    platforms = ANDROID,
+    platforms = (ANDROID, APPLE, CXX),
     deps = [
         "//xplat/third-party/gmock:gtest",
         react_native_xplat_target("react/debug:debug"),