tester checks exitcode; osproc additions; DLL fixes; taint mode fixes

tests/dll/server.nim

@@ -0,0 +1,27 @@
+discard """
+  cmd: "nimrod cc --debuginfo --hints:on --define:useNimRtl --app:lib $# $#"
+"""
+
+type
+  TNodeKind = enum nkLit, nkSub, nkAdd, nkDiv, nkMul
+  TNode = object
+    case k: TNodeKind
+    of nkLit: x: int
+    else: a, b: ref TNode
+
+  PNode = ref TNode
+    
+proc newLit(x: int): PNode {.exportc: "newLit", dynlib.} =
+  new(result)
+  result.x = x
+  
+proc newOp(k: TNodeKind, a, b: PNode): PNode {.exportc: "newOp", dynlib.} =
+  assert a != nil
+  assert b != nil
+  new(result)
+  result.k = k
+  result.a = a
+  result.b = b
+  
+proc buildTree(x: int): PNode {.exportc: "buildTree", dynlib.} = 
+  result = newOp(nkMul, newOp(nkAdd, newLit(x), newLit(x)), newLit(x))