[SPARK-9211] [SQL] [TEST] normalize line separators before generating MD5 hash

The golden answer file names for the existing Hive comparison tests were generated using a MD5 hash of the query text which uses Unix-style line separator characters `\n` (LF).
This PR ensures that all occurrences of the Windows-style line separator `\r\n` (CR) are replaced with `\n` (LF) before generating the MD5 hash to produce an identical MD5 hash for golden answer file names generated on Windows.

Author: Christian Kadner <ckadner@us.ibm.com>

Closes #7563 from ckadner/SPARK-9211_working and squashes the following commits:

d541db0 [Christian Kadner] [SPARK-9211][SQL] normalize line separators before MD5 hash

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveComparisonTest.scala

@@ -124,7 +124,7 @@ abstract class HiveComparisonTest
   protected val cacheDigest = java.security.MessageDigest.getInstance("MD5")
   protected def getMd5(str: String): String = {
     val digest = java.security.MessageDigest.getInstance("MD5")
-    digest.update(str.getBytes("utf-8"))
+    digest.update(str.replaceAll(System.lineSeparator(), "\n").getBytes("utf-8"))
     new java.math.BigInteger(1, digest.digest).toString(16)
   }
 

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveQuerySuite.scala

@@ -427,7 +427,7 @@ class HiveQuerySuite extends HiveComparisonTest with BeforeAndAfter {
       |'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe'
       |USING 'cat' AS (tKey, tValue) ROW FORMAT SERDE
       |'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe' FROM src;
-    """.stripMargin.replaceAll("\n", " "))
+    """.stripMargin.replaceAll(System.lineSeparator(), " "))
 
   test("transform with SerDe2") {
 
@@ -446,7 +446,7 @@ class HiveQuerySuite extends HiveComparisonTest with BeforeAndAfter {
         |('avro.schema.literal'='{"namespace": "testing.hive.avro.serde","name":
         |"src","type": "record","fields": [{"name":"key","type":"int"}]}')
         |FROM small_src
-      """.stripMargin.replaceAll("\n", " ")).collect().head
+      """.stripMargin.replaceAll(System.lineSeparator(), " ")).collect().head
 
     assert(expected(0) === res(0))
   }
@@ -458,7 +458,7 @@ class HiveQuerySuite extends HiveComparisonTest with BeforeAndAfter {
       |('serialization.last.column.takes.rest'='true') USING 'cat' AS (tKey, tValue)
       |ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe'
       |WITH SERDEPROPERTIES ('serialization.last.column.takes.rest'='true') FROM src;
-    """.stripMargin.replaceAll("\n", " "))
+    """.stripMargin.replaceAll(System.lineSeparator(), " "))
 
   createQueryTest("transform with SerDe4",
     """
@@ -467,7 +467,7 @@ class HiveQuerySuite extends HiveComparisonTest with BeforeAndAfter {
       |('serialization.last.column.takes.rest'='true') USING 'cat' ROW FORMAT SERDE
       |'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe' WITH SERDEPROPERTIES
       |('serialization.last.column.takes.rest'='true') FROM src;
-    """.stripMargin.replaceAll("\n", " "))
+    """.stripMargin.replaceAll(System.lineSeparator(), " "))
 
   createQueryTest("LIKE",
     "SELECT * FROM src WHERE value LIKE '%1%'")