A motivating example for the new bindSym behavior.

The example is a proof-of-concept logging library, allowing you to define
lexically-scoped environments where certain logging attributes are applied
automatically to all logging statements.

fixes tmacro1 (use of `bindSym` inside static blocks)

compiler/semmagic.nim

@@ -199,7 +199,7 @@ proc semBindSym(c: PContext, n: PNode): PNode =
   if s != nil:
     # we need to mark all symbols:
     var sc = symChoice(c, id, s, TSymChoiceRule(isMixin.intVal))
-    if not getCurrOwner(c).isCompileTimeProc:
+    if not (c.inStaticContext > 0 or getCurrOwner(c).isCompileTimeProc):
       # inside regular code, bindSym resolves to the sym-choice
       # nodes (see tinspectsymbol)
       return sc