Fix databricks build for AQE support (NVIDIA#560)

Signed-off-by: Thomas Graves <tgraves@nvidia.com>

shims/spark300db/src/main/scala/com/nvidia/spark/rapids/shims/spark300db/GpuBroadcastExchangeExec.scala

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2020, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.nvidia.spark.rapids.shims.spark300db
+
+import org.apache.spark.sql.catalyst.plans.physical.BroadcastMode
+import org.apache.spark.sql.execution.SparkPlan
+import org.apache.spark.sql.rapids.execution.{GpuBroadcastExchangeExec, GpuBroadcastExchangeExecBase}
+
+case class GpuBroadcastExchangeExec(
+    mode: BroadcastMode,
+    child: SparkPlan) extends GpuBroadcastExchangeExecBase(mode, child) {
+
+  override def doCanonicalize(): SparkPlan = {
+    GpuBroadcastExchangeExec(mode.canonicalized, child.canonicalized)
+  }
+}

shims/spark300db/src/main/scala/com/nvidia/spark/rapids/shims/spark300db/GpuBroadcastHashJoinExec.scala

@@ -26,10 +26,11 @@ import org.apache.spark.sql.catalyst.optimizer.{BuildLeft, BuildRight, BuildSide
 import org.apache.spark.sql.catalyst.plans.JoinType
 import org.apache.spark.sql.catalyst.plans.physical.{BroadcastDistribution, Distribution, UnspecifiedDistribution}
 import org.apache.spark.sql.execution.{BinaryExecNode, SparkPlan}
+import org.apache.spark.sql.execution.adaptive.BroadcastQueryStageExec
 import org.apache.spark.sql.execution.exchange.ReusedExchangeExec
 import org.apache.spark.sql.execution.joins.{BroadcastHashJoinExec, HashedRelationBroadcastMode}
 import org.apache.spark.sql.execution.metric.{SQLMetric, SQLMetrics}
-import org.apache.spark.sql.rapids.execution.{GpuBroadcastExchangeExec, SerializeConcatHostBuffersDeserializeBatch}
+import org.apache.spark.sql.rapids.execution.SerializeConcatHostBuffersDeserializeBatch
 import org.apache.spark.sql.vectorized.ColumnarBatch
 
 /**
@@ -113,6 +114,9 @@ case class GpuBroadcastHashJoinExec(
   }
 
   def broadcastExchange: GpuBroadcastExchangeExec = buildPlan match {
+    case BroadcastQueryStageExec(_, gpu: GpuBroadcastExchangeExec, _) => gpu
+    case BroadcastQueryStageExec(_, reused: ReusedExchangeExec, _) =>
+      reused.child.asInstanceOf[GpuBroadcastExchangeExec]
     case gpu: GpuBroadcastExchangeExec => gpu
     case reused: ReusedExchangeExec => reused.child.asInstanceOf[GpuBroadcastExchangeExec]
   }

shims/spark300db/src/main/scala/com/nvidia/spark/rapids/shims/spark300db/Spark300dbShims.scala

@@ -31,7 +31,6 @@ import org.apache.spark.sql.execution.joins.{BroadcastHashJoinExec, BroadcastNes
 import org.apache.spark.sql.execution.joins.ShuffledHashJoinExec
 import org.apache.spark.sql.rapids.{GpuFileSourceScanExec, GpuTimeSub}
 import org.apache.spark.sql.rapids.execution.GpuBroadcastNestedLoopJoinExecBase
-import org.apache.spark.sql.rapids.shims.spark300db._
 import org.apache.spark.sql.types._
 import org.apache.spark.storage.{BlockId, BlockManagerId}