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/build/BuildReport.py

@@ -1626,7 +1626,7 @@ class PredictionReport(object):
         TempFile.close()
 
         try:
-            from Eot.Eot import Eot
+            from Eot.EotMain import Eot
 
             #
             # Invoke EOT tool and echo its runtime performance