added experimental .this pragma

compiler/sigmatch.nim

@@ -37,6 +37,7 @@ type
                              # is this a top-level symbol or a nested proc?
     call*: PNode             # modified call
     bindings*: TIdTable      # maps types to types
+    magic*: TMagic           # magic of operation
     baseTypeMatch: bool      # needed for conversions from T to openarray[T]
                              # for example
     fauxMatch*: TTypeKind    # the match was successful only due to the use
@@ -114,6 +115,7 @@ proc initCandidate*(ctx: PContext, c: var TCandidate, callee: PSym,
       c.calleeScope = 1
   else:
     c.calleeScope = calleeScope
+  c.magic = c.calleeSym.magic
   initIdTable(c.bindings)
   c.errors = nil
   if binding != nil and callee.kind in routineKinds:
@@ -1691,7 +1693,7 @@ proc partialMatch*(c: PContext, n, nOrig: PNode, m: var TCandidate) =
   matchesAux(c, n, nOrig, m, marker)
 
 proc matches*(c: PContext, n, nOrig: PNode, m: var TCandidate) =
-  if m.calleeSym != nil and m.calleeSym.magic in {mArrGet, mArrPut}:
+  if m.magic in {mArrGet, mArrPut}:
     m.state = csMatch
     m.call = n
     return