Revert "Add more API fuzzing and fix the issues encountered."

runtime/bin/builtin_natives.cc

Index: runtime/bin/builtin_natives.cc
diff --git a/runtime/bin/builtin_natives.cc b/runtime/bin/builtin_natives.cc
index 875886eac1a038239ac5a2132ed280d2b3723161..eadd3296886852f8086ee33395396f9fd1981b28 100644
--- a/runtime/bin/builtin_natives.cc
+++ b/runtime/bin/builtin_natives.cc
@@ -129,9 +129,7 @@ void FUNCTION_NAME(Logger_PrintString)(Dart_NativeArguments args) {
 
 void FUNCTION_NAME(Exit)(Dart_NativeArguments args) {
   Dart_EnterScope();
-  int64_t status = 0;
-  // Ignore result if passing invalid argument and just exit 0.
-  DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 0), &status);
+  int64_t status = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   Dart_ExitScope();
   exit(status);
 }