Try to change some logic for contextual narrowing for any instantiable type to empty objects.

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -25317,7 +25317,7 @@ namespace ts {
             return !!(type.flags & TypeFlags.Instantiable && !maybeTypeOfKind(getBaseConstraintOrType(type), TypeFlags.Nullable));
         }
 
-        function hasContextualTypeWithNoGenericTypes(node: Node, checkMode: CheckMode | undefined) {
+        function tryGetContextualTypeWithNoGenericTypes(node: Node, checkMode: CheckMode | undefined) {
             // Computing the contextual type for a child of a JSX element involves resolving the type of the
             // element's tag name, so we exclude that here to avoid circularities.
             // If check mode has `CheckMode.RestBindingElement`, we skip binding pattern contextual types,
@@ -25327,7 +25327,7 @@ namespace ts {
                 (checkMode && checkMode & CheckMode.RestBindingElement ?
                     getContextualType(node, ContextFlags.SkipBindingPatterns)
                     : getContextualType(node));
-            return contextualType && !isGenericType(contextualType);
+            return contextualType && !isGenericType(contextualType) ? contextualType : undefined;
         }
 
         function getNarrowableTypeForReference(type: Type, reference: Node, checkMode?: CheckMode) {
@@ -25338,9 +25338,13 @@ namespace ts {
             // control flow analysis an opportunity to narrow it further. For example, for a reference of a type
             // parameter type 'T extends string | undefined' with a contextual type 'string', we substitute
             // 'string | undefined' to give control flow analysis the opportunity to narrow to type 'string'.
+            let contextualType: Type | undefined;
             const substituteConstraints = !(checkMode && checkMode & CheckMode.Inferential) &&
-                someType(type, isGenericTypeWithUnionConstraint) &&
-                (isConstraintPosition(type, reference) || hasContextualTypeWithNoGenericTypes(reference, checkMode));
+                (isConstraintPosition(type, reference) || (contextualType = tryGetContextualTypeWithNoGenericTypes(reference, checkMode))) &&
+                (
+                    someType(type, isGenericTypeWithUnionConstraint) ||
+                    ((type.flags & TypeFlags.Instantiable) && contextualType && isEmptyObjectType(contextualType))
+                );
             return substituteConstraints ? mapType(type, t => t.flags & TypeFlags.Instantiable ? getBaseConstraintOrType(t) : t) : type;
         }