BaseTools/Ecc/EOT: Add Python 3 support on ECC and EOT tools.

1. Add Python 3 support on ECC and EOT tools
2. Add C grammar file of ANTLR4 and fix some bugs

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hess Chen <hesheng.chen@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

BaseTools/Source/Python/Common/Misc.py

@@ -988,7 +988,7 @@ class sdict(IterableUserDict):
 
     ## append support
     def append(self, sdict):
-        for key in sdict:
+        for key in sdict.keys():
             if key not in self._key_list:
                 self._key_list.append(key)
             IterableUserDict.__setitem__(self, key, sdict[key])