[esnext] prototype runtime implementation for async functions

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index ca9cccd32b2a7ce9f62d8255513e90f17e35eff2..acf1989c0cfb082edb159831fe13f32f0c91c2ba 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -505,6 +505,11 @@ bool UseIgnition(CompilationInfo* info) {
     return false;
   }
 
+  if (info->shared_info()->is_async()) {
+    // TODO(caitp): plug this into ignition generators
+    return false;
+  }
+
   // Checks whether top level functions should be passed by the filter.
   if (info->shared_info()->is_toplevel()) {
     Vector<const char> filter = CStrVector(FLAG_ignition_filter);