[embedded] Force deserialization of wtables when needed to support class-bound existentials

test/embedded/existential-class-bound8.swift

@@ -0,0 +1,34 @@
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+
+// RUN: %target-swift-frontend -emit-module -o %t/MyModule.swiftmodule %t/MyModule.swift -enable-experimental-feature Embedded -parse-as-library
+// RUN: %target-swift-frontend -c -I %t %t/Main.swift -enable-experimental-feature Embedded -o %t/a.o
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: OS=macosx || OS=linux-gnu
+
+// BEGIN MyModule.swift
+
+public protocol ClassBound: AnyObject {
+    func foo()
+}
+
+class MyGenericClass<T> {
+    var typ: String
+    init(typ: String) { self.typ = typ }
+}
+extension MyGenericClass: ClassBound {
+    func foo() { print("MyGenericClass<\(typ)>.foo()") }
+}
+
+public func factory() -> any ClassBound {
+    return MyGenericClass<String>(typ: "String")
+}
+
+// BEGIN Main.swift
+
+import MyModule
+
+var arr: [any ClassBound] = [factory()]
+arr[0].foo()
+// CHECK: MyGenericClass<String>.foo()