Remove strong mode support from materialized literals.

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index dc34e8254e3c671c9c152c8f7be5aab3c986a379..a50eee99ee0b9d2f4f272ab619a1821030bd0a14 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -1337,14 +1337,11 @@ class MaterializedLiteral : public Expression {
     return depth_;
   }
 
-  bool is_strong() const { return is_strong_; }
-
  protected:
-  MaterializedLiteral(Zone* zone, int literal_index, bool is_strong, int pos)
+  MaterializedLiteral(Zone* zone, int literal_index, int pos)
       : Expression(zone, pos),
         literal_index_(literal_index),
         is_simple_(false),
-        is_strong_(is_strong),
         depth_(0) {}
 
   // A materialized literal is simple if the values consist of only
@@ -1373,7 +1370,6 @@ class MaterializedLiteral : public Expression {
  private:
   int literal_index_;
   bool is_simple_;
-  bool is_strong_;
   int depth_;
 
   friend class AstLiteralReindexer;
@@ -1488,9 +1484,6 @@ class ObjectLiteral final : public MaterializedLiteral {
     if (disable_mementos) {
       flags |= kDisableMementos;
     }
-    if (is_strong()) {
-      flags |= kIsStrong;
-    }
     return flags;
   }
 
@@ -1499,8 +1492,7 @@ class ObjectLiteral final : public MaterializedLiteral {
     kFastElements = 1,
     kHasFunction = 1 << 1,
     kShallowProperties = 1 << 2,
-    kDisableMementos = 1 << 3,
-    kIsStrong = 1 << 4
+    kDisableMementos = 1 << 3
   };
 
   struct Accessors: public ZoneObject {
@@ -1532,9 +1524,8 @@ class ObjectLiteral final : public MaterializedLiteral {
 
  protected:
   ObjectLiteral(Zone* zone, ZoneList<Property*>* properties, int literal_index,
-                int boilerplate_properties, bool has_function, bool is_strong,
-                int pos)
-      : MaterializedLiteral(zone, literal_index, is_strong, pos),
+                int boilerplate_properties, bool has_function, int pos)
+      : MaterializedLiteral(zone, literal_index, pos),
         properties_(properties),
         boilerplate_properties_(boilerplate_properties),
         fast_elements_(false),
@@ -1587,8 +1578,8 @@ class RegExpLiteral final : public MaterializedLiteral {
 
  protected:
   RegExpLiteral(Zone* zone, const AstRawString* pattern, int flags,
-                int literal_index, bool is_strong, int pos)
-      : MaterializedLiteral(zone, literal_index, is_strong, pos),
+                int literal_index, int pos)
+      : MaterializedLiteral(zone, literal_index, pos),
         pattern_(pattern),
         flags_(flags) {
     set_depth(1);
@@ -1633,9 +1624,6 @@ class ArrayLiteral final : public MaterializedLiteral {
     if (disable_mementos) {
       flags |= kDisableMementos;
     }
-    if (is_strong()) {
-      flags |= kIsStrong;
-    }
     return flags;
   }
 
@@ -1655,8 +1643,7 @@ class ArrayLiteral final : public MaterializedLiteral {
   enum Flags {
     kNoFlags = 0,
     kShallowElements = 1,
-    kDisableMementos = 1 << 1,
-    kIsStrong = 1 << 2
+    kDisableMementos = 1 << 1
   };
 
   void AssignFeedbackVectorSlots(Isolate* isolate, FeedbackVectorSpec* spec,
@@ -1665,9 +1652,8 @@ class ArrayLiteral final : public MaterializedLiteral {
 
  protected:
   ArrayLiteral(Zone* zone, ZoneList<Expression*>* values,
-               int first_spread_index, int literal_index, bool is_strong,
-               int pos)
-      : MaterializedLiteral(zone, literal_index, is_strong, pos),
+               int first_spread_index, int literal_index, int pos)
+      : MaterializedLiteral(zone, literal_index, pos),
         values_(values),
         first_spread_index_(first_spread_index) {}
   static int parent_num_ids() { return MaterializedLiteral::num_ids(); }
@@ -3242,11 +3228,10 @@ class AstNodeFactory final BASE_EMBEDDED {
       int literal_index,
       int boilerplate_properties,
       bool has_function,
-      bool is_strong,
       int pos) {
     return new (local_zone_)
         ObjectLiteral(local_zone_, properties, literal_index,
-                      boilerplate_properties, has_function, is_strong, pos);
+                      boilerplate_properties, has_function, pos);
   }
 
   ObjectLiteral::Property* NewObjectLiteralProperty(
@@ -3265,24 +3250,23 @@ class AstNodeFactory final BASE_EMBEDDED {
   }
 
   RegExpLiteral* NewRegExpLiteral(const AstRawString* pattern, int flags,
-                                  int literal_index, bool is_strong, int pos) {
-    return new (local_zone_) RegExpLiteral(local_zone_, pattern, flags,
-                                           literal_index, is_strong, pos);
+                                  int literal_index, int pos) {
+    return new (local_zone_)
+        RegExpLiteral(local_zone_, pattern, flags, literal_index, pos);
   }
 
   ArrayLiteral* NewArrayLiteral(ZoneList<Expression*>* values,
                                 int literal_index,
-                                bool is_strong,
                                 int pos) {
     return new (local_zone_)
-        ArrayLiteral(local_zone_, values, -1, literal_index, is_strong, pos);
+        ArrayLiteral(local_zone_, values, -1, literal_index, pos);
   }
 
   ArrayLiteral* NewArrayLiteral(ZoneList<Expression*>* values,
                                 int first_spread_index, int literal_index,
-                                bool is_strong, int pos) {
+                                int pos) {
     return new (local_zone_) ArrayLiteral(
-        local_zone_, values, first_spread_index, literal_index, is_strong, pos);
+        local_zone_, values, first_spread_index, literal_index, pos);
   }
 
   VariableProxy* NewVariableProxy(Variable* var,