Fix: disallow cast from module class to virtual metaclass (#6320)

spec/compiler/semantic/module_spec.cr

@@ -1259,4 +1259,26 @@ describe "Semantic: module" do
       ),
       "can't declare instance variables in Bar:Class"
   end
+
+  it "can't pass module class to virtual metaclass (#6113)" do
+    assert_error %(
+      module Moo
+      end
+
+      class Foo
+      end
+
+      class Bar < Foo
+        include Moo
+      end
+
+      class Gen(T)
+        def self.foo(x : T)
+        end
+      end
+
+      Gen(Foo.class).foo(Moo)
+      ),
+      "no overload matches"
+  end
 end

src/compiler/crystal/semantic/restrictions.cr

@@ -953,6 +953,9 @@ module Crystal
     end
 
     def restrict(other : VirtualMetaclassType, context)
+      # A module class can't be restricted into a class
+      return nil if instance_type.module?
+
       restricted = instance_type.restrict(other.instance_type.base_type, context)
       restricted ? self : nil
     end