[esnext] implement frontend changes for async/await proposal

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 0d61bc9a5228ae28ea5382d023bb377f1e9b2cbc..790df6ab6fcd283c97bd48046b1a2078b8c4eaf7 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4365,7 +4365,7 @@ class ScopeInfo : public FixedArray {
   class HasSimpleParametersField
       : public BitField<bool, AsmFunctionField::kNext, 1> {};
   class FunctionKindField
-      : public BitField<FunctionKind, HasSimpleParametersField::kNext, 8> {};
+      : public BitField<FunctionKind, HasSimpleParametersField::kNext, 9> {};
 
   // BitFields representing the encoded information for context locals in the
   // ContextLocalInfoEntries part.
@@ -7212,6 +7212,7 @@ class SharedFunctionInfo: public HeapObject {
     kIsGetterFunction,
     kIsSetterFunction,
     // byte 3
+    kIsAsyncFunction,
     kDeserialized,
     kIsDeclaration,
     kCompilerHintsCount,  // Pseudo entry
@@ -7234,7 +7235,7 @@ class SharedFunctionInfo: public HeapObject {
   ASSERT_FUNCTION_KIND_ORDER(kSetterFunction, kIsSetterFunction);
 #undef ASSERT_FUNCTION_KIND_ORDER
 
-  class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 8> {};
+  class FunctionKindBits : public BitField<FunctionKind, kIsArrow, 9> {};
 
   class DeoptCountBits : public BitField<int, 0, 4> {};
   class OptReenableTriesBits : public BitField<int, 4, 18> {};