[flow][refactor] Introduce use_unsound_fallback flag to Reason.mk_obj_lit_reason

Summary:
Will be used later to implement a partial fix for unsound object literals.

Changelog: [internal]

Reviewed By: panagosg7

Differential Revision: D76283490

fbshipit-source-id: e67790e089c0736660df2b77eeda7fe66339dd07

Author: SamChou19815

src/common/reason.ml

@@ -494,14 +494,16 @@ let def_loc_of_reason r =
 
 let annot_loc_of_reason r = r.annot_loc_opt
 
-let mk_obj_lit_reason ~as_const ~frozen loc =
+let mk_obj_lit_reason ~as_const ~frozen ~use_unsound_fallback loc =
   let desc =
     if frozen then
       RFrozen RObjectLit
     else if as_const then
       RConstObjectLit
-    else
+    else if Lazy.force use_unsound_fallback then
       RObjectLit_UNSOUND
+    else
+      RObjectLit
   in
   mk_reason desc loc
 

src/common/reason.mli

@@ -342,7 +342,8 @@ val opt_annot_reason : ?annot_loc:'loc -> 'loc virtual_reason -> 'loc virtual_re
 (* create a new reason with annot_loc = loc: same as mk_reason followed by annot_reason *)
 val mk_annot_reason : 'loc virtual_reason_desc -> 'loc -> 'loc virtual_reason
 
-val mk_obj_lit_reason : as_const:bool -> frozen:bool -> 'loc -> 'loc virtual_reason
+val mk_obj_lit_reason :
+  as_const:bool -> frozen:bool -> use_unsound_fallback:bool Lazy.t -> 'loc -> 'loc virtual_reason
 
 module ReasonMap : WrappedMap.S with type key = reason
 

src/typing/statement.ml

@@ -2488,7 +2488,7 @@ module Make
   and object_ cx ~frozen ~as_const ~has_hint loc props =
     let open Ast.Expression.Object in
     error_on_this_uses_in_object_methods cx props;
-    let reason = Reason.mk_obj_lit_reason ~as_const ~frozen loc in
+    let reason = Reason.mk_obj_lit_reason ~as_const ~frozen ~use_unsound_fallback:(lazy true) loc in
     (* Use the same reason for proto and the ObjT so we can walk the proto chain
        and use the root proto reason to build an error. *)
     let obj_proto = ObjProtoT reason in

src/typing/type_sig_merge.ml

@@ -1203,7 +1203,7 @@ and merge_declare_module_implicitly_exported_object env file (loc, module_name,
   Obj_type.mk_with_proto file.cx reason proto ~obj_kind:Type.Exact ~props
 
 and merge_object_lit ~for_export ~as_const env file (loc, frozen, proto, props) =
-  let reason = Reason.mk_obj_lit_reason ~as_const ~frozen loc in
+  let reason = Reason.mk_obj_lit_reason ~as_const ~frozen ~use_unsound_fallback:(lazy true) loc in
   let proto =
     match proto with
     | None -> Type.ObjProtoT reason
@@ -1219,7 +1219,7 @@ and merge_object_lit ~for_export ~as_const env file (loc, frozen, proto, props)
   Obj_type.mk_with_proto file.cx reason proto ~obj_kind:Type.Exact ~props
 
 and merge_obj_spread_lit ~for_export ~as_const env file (loc, frozen, proto, elems_rev) =
-  let reason = Reason.mk_obj_lit_reason ~as_const ~frozen loc in
+  let reason = Reason.mk_obj_lit_reason ~as_const ~frozen ~use_unsound_fallback:(lazy true) loc in
   (* TODO: fix spread to use provided __proto__ prop *)
   ignore proto;
   let merge_slice props =