Implement the function.sent proposal.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 1a763b8035d1eb46a26948b516512d408eb1b3ea..36ae5782c3dca99ec4b80c5e902220776fb24424 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2319,6 +2319,7 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_tolength)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_do_expressions)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexp_lookbehind)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_function_name)
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_function_sent)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(promise_extra)
 
 
@@ -2857,6 +2858,7 @@ bool Genesis::InstallExperimentalNatives() {
   static const char* harmony_regexp_subclass_natives[] = {nullptr};
   static const char* harmony_regexp_lookbehind_natives[] = {nullptr};
   static const char* harmony_function_name_natives[] = {nullptr};
+  static const char* harmony_function_sent_natives[] = {nullptr};
   static const char* promise_extra_natives[] = {"native promise-extra.js",
                                                 nullptr};