[typer] don't hide abstract type when resolving through @:forward

closes #11526

src/typing/fields.ml

@@ -270,7 +270,7 @@ let type_field cfg ctx e i p mode (with_type : WithType.t) =
 		| None -> raise Not_found
 	in
 	let type_field_by_et f e t =
-		f { e with etype = t } (follow_without_type t)
+		f (mk (TCast(e,None)) t e.epos) (follow_without_type t)
 	in
 	let type_field_by_e f e =
 		f e (follow_without_type e.etype)

tests/optimization/src/TestInlineConstructors.hx

@@ -44,6 +44,19 @@ class NestedInlineClass {
 	}
 }
 
+class P {
+	public var x:Float;
+
+	public inline function new(x = 0)
+		this.x = x;
+}
+
+@:forward
+abstract PA(P) to P {
+	public inline function new(x)
+		this = new P(x);
+}
+
 class TestInlineConstructors extends TestBase {
 	@:js('return [1,2,3,3];')
 	static function testArrayInlining() {
@@ -147,4 +160,10 @@ class TestInlineConstructors extends TestBase {
 		try { a; } catch(_) { a; };
 		return a.a;
 	}
+
+	@:js('return [5];')
+	static function testForwardAbstract() {
+		var p2 = {v: new PA(5)};
+		return [p2.v.x];
+	}
 }