slices are first class citizens

tests/accept/compile/ttableconstr.nim

@@ -0,0 +1,16 @@
+# Test if the new table constructor syntax works:
+
+template ignoreExpr(e: expr): stmt =
+  nil
+
+# test first class '..' syntactical citizen:  
+ignoreExpr x <> 2..4
+# test table constructor:
+ignoreExpr({:})
+ignoreExpr({2: 3, "key": "value"})
+
+# NEW:
+assert 56 in 50..100
+
+assert 56 in ..60
+