further improvements for term rewriting macros

tests/patterns/tstmtlist.nim

@@ -0,0 +1,18 @@
+discard """
+  output: '''0
+|12|34
+'''
+"""
+
+template optWrite{
+  write(stdout, x)
+  write(stdout, y)
+}(x, y: string) =
+  write(stdout, "|", x, y, "|")
+
+if true:
+  echo "0"
+  write stdout, "1"
+  write stdout, "2"
+  write stdout, "3"
+  echo "4"