[flash] remove `untyped` from `EReg`

it's already Dynamic, so why untyped?:)

std/flash/_std/EReg.hx

@@ -40,20 +40,20 @@
 
 	public function matchedLeft() : String {
 		if( result == null ) throw "No string matched";
-		var s : String = untyped result.input;
-		return s.substr(0,untyped result["index"]);
+		var s : String = result.input;
+		return s.substr(0, result.index);
 	}
 
 	public function matchedRight() : String {
 		if( result == null ) throw "No string matched";
-		var rl = (result[untyped "index"] : Int) + (result[0] : String).length;
-		var s : String = untyped result.input;
+		var rl = (result.index : Int) + (result[0] : String).length;
+		var s : String = result.input;
 		return s.substr(rl,s.length - rl);
 	}
 
 	public function matchedPos() : { pos : Int, len : Int } {
 		if( result == null ) throw "No string matched";
-		return { pos : result[untyped "index"], len : (result[0] : String).length };
+		return { pos : result.index, len : (result[0] : String).length };
 	}
 
 	public function matchSub( s : String, pos : Int, len : Int = -1):Bool {
@@ -62,14 +62,14 @@
 			result = r.exec(len < 0 ? s : s.substr(0, pos + len));
 			var b = result != null;
 			if (b) {
-				untyped result.input = s;
+				result.input = s;
 			}
 			b;
 		} else {
 			var b = match( len < 0 ? s.substr(pos) : s.substr(pos,len) );
 			if (b) {
-				untyped result.input = s;
-				untyped result["index"] += pos;
+				result.input = s;
+				result.index += pos;
 			}
 			b;
 		}
@@ -78,12 +78,12 @@
 	public function split( s : String ) : Array<String> {
 		// we can't use directly s.split because it's ignoring the 'g' flag
 		var d = "#__delim__#";
-		var s : String = untyped s.replace(r, d);
+		var s : String = (cast s).replace(r, d);
 		return s.split(d);
 	}
 
 	public function replace( s : String, by : String ) : String {
-		return untyped s.replace(r,by);
+		return (cast s).replace(r,by);
 	}
 
 	public function map( s : String, f : EReg -> String ) : String {