[PROD-1622][PROD-8140] Backport SI-9734 for Scala 2.10

This was done by zsxwing in databricks/universe@462da3a

(cherry picked from commit b7555a5b947ee41ee017ac5d0be78795868ff54f)
Signed-off-by: Herman van Hovell <hvanhovelldatabricks.com>

Author: Reynold Xin <[email protected]>

Closes apache#121 from hvanhovell/PROD-1622-21.

Author: rxin

repl/scala-2.10/src/main/scala/org/apache/spark/repl/SparkImports.scala

@@ -190,7 +190,7 @@ private[repl] trait SparkImports {
             val valName = "$VAL" + newValId();
 
             if(!code.toString.endsWith(".`" + imv + "`;\n")) { // Which means already imported
-               code.append("val " + valName + " = " + objName + ".INSTANCE;\n")
+               code.append(s"val $valName: ${objName}.INSTANCE.type = ${objName}.INSTANCE;\n")
                code.append("import " + valName + req.accessPath + ".`" + imv + "`;\n")
             }
             // code.append("val " + valName + " = " + objName + ".INSTANCE;\n")

repl/scala-2.10/src/test/scala/org/apache/spark/repl/ReplSuite.scala

@@ -355,5 +355,16 @@ class ReplSuite extends SparkFunSuite {
     assertDoesNotContain("Exception", output)
     assertContains("ret: Array[(Int, Iterable[Foo])] = Array((1,", output)
   }
+
+  test("SI-9734 class defined with paste mode mismatches") {
+    val output = runInterpreter("local",
+      """
+        |case class Data(i: Int); val d = Data(1)
+        |val d2: Data = d
+      """.stripMargin)
+    assertDoesNotContain("error:", output)
+    assertDoesNotContain("Exception", output)
+    assertContains("d2: Data = Data(1)", output)
+  }
 }