Added some tests for the while

ucl/testbuiltins_test.go

@@ -294,6 +294,16 @@ func TestBuiltins_While(t *testing.T) {
 				set x (add $x 1)
 			}
 			echo "done"`, want: "done\n(nil)\n"},
+		{desc: "iterate while true with pipeline", expr: `
+			set x 0
+			while (lt $x 5) {
+				echo $x
+				set x (add $x 1)
+				if (ge $x 3) {
+					break "Ahh"
+				}
+			} | echo " was the break"
+			echo "done"`, want: "0\n1\n2\nAhh was the break\ndone\n(nil)\n"},
 		{desc: "iterate for ever with break 1", expr: `
 			set x 0
 			while {