Add bin to FunctionRegistry.

Author: viirya

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala

@@ -122,6 +122,7 @@ object FunctionRegistry {
     expression[Tanh]("tanh"),
     expression[ToDegrees]("todegrees"),
     expression[ToRadians]("toradians"),
+    expression[Bin]("bin"),
 
     // aggregate functions
     expression[Average]("avg"),