add System.out::println native method for CSEC machine

Author: mattcce

src/ec-evaluator/lib.ts

@@ -35,12 +35,19 @@ export class LFSR {
 
 export const libraryClasses = `
 class Object {
-  public static native void display(int s);
-
   public native int hashCode();
 
   public native String toString();
-}`
+}
+
+class PrintStream {
+  public static native void println(String s);
+}
+  
+class System {
+  public static PrintStream out = new PrintStream();
+}
+`
 
 // const disabled = `class PrintStream extends Object {
 //   public native void println(String s);

src/ec-evaluator/natives.ts

@@ -44,7 +44,7 @@ export const foreigns: {
     stash.push(stashItem)
   },
 
-  'Object::display(int s): void': ({ environment, interfaces }) => {
+  'PrintStream::println(String s): void': ({ environment, interfaces }) => {
     // @ts-expect-error ts(2339): guaranteed valid by type checker
     const s = environment.getVariable('s').value.literalType.value