Revert 'isEmpty' transformation

compiler/testData/codegen/boxWithJava/builtinStubMethods/substitutedList/substitutedList.kt

@@ -1,6 +1,6 @@
 abstract class C : Test.A, List<String> {
     override val size: Int get() = null!!
-    override val isEmpty: Boolean get() = null!!
+    override fun isEmpty(): Boolean = null!!
     override fun contains(o: String): Boolean = null!!
     override fun iterator(): Iterator<String> = null!!
     override fun containsAll(c: Collection<String>): Boolean = null!!

compiler/testData/codegen/boxWithJava/collections/mutableList/mutableList.kt

@@ -58,7 +58,7 @@ open class KList<E> : MutableList<E> {
     override val size: Int
         get() = throw UnsupportedOperationException()
 
-    override val isEmpty: Boolean get() {
+    override fun isEmpty(): Boolean {
         throw UnsupportedOperationException()
     }
 

compiler/testData/codegen/boxWithJava/collections/removeAtInt/removeAtInt.kt

@@ -1,8 +1,7 @@
 open class A : MutableList<Int> {
     override val size: Int
         get() = throw UnsupportedOperationException()
-    override val isEmpty: Boolean
-        get() = throw UnsupportedOperationException()
+    override fun isEmpty(): Boolean = throw UnsupportedOperationException()
 
     override fun contains(o: Int): Boolean {
         throw UnsupportedOperationException()

compiler/testData/codegen/boxWithJava/collections/strList/strList.kt

@@ -2,7 +2,7 @@ open class KList : MutableList<String> {
     override val size: Int
         get() = throw UnsupportedOperationException()
 
-    override val isEmpty: Boolean get() {
+    override fun isEmpty(): Boolean {
         throw UnsupportedOperationException()
     }