Tests: remove stepping tests on old JVM backend

compiler/testData/debug/stepping/whenMultiLine.kt

@@ -29,54 +29,27 @@ fun box() {
     foo(63)
 }
 
-// JVM_IR backend optimized the when to a switch in the java bytecode.
-// Therefore, the stepping for JVM_IR does not step through the evaluation
-// of each of the conditions, but goes directly to the right body.
-// JVM_IR stepping behavior here is the same as for `whenMultiLineSubject.kt`.
-
-// EXPECTATIONS JVM JVM_IR
+// EXPECTATIONS JVM_IR
 // test.kt:27 box
 // test.kt:5 foo
-// EXPECTATIONS JVM
-// test.kt:6 foo
-// EXPECTATIONS JVM JVM_IR
 // test.kt:7 foo
 // test.kt:14 foo
-// EXPECTATIONS JVM
-// test.kt:15 foo
-// EXPECTATIONS JVM JVM_IR
 // test.kt:16 foo
 // test.kt:14 foo
 // test.kt:23 foo
 // test.kt:27 box
 // test.kt:28 box
 // test.kt:5 foo
-// EXPECTATIONS JVM
-// test.kt:6 foo
-// test.kt:8 foo
-// EXPECTATIONS JVM JVM_IR
 // test.kt:9 foo
 // test.kt:14 foo
-// EXPECTATIONS JVM
-// test.kt:15 foo
-// test.kt:17 foo
-// EXPECTATIONS JVM JVM_IR
 // test.kt:18 foo
 // test.kt:14 foo
 // test.kt:23 foo
 // test.kt:28 box
 // test.kt:29 box
 // test.kt:5 foo
-// EXPECTATIONS JVM
-// test.kt:6 foo
-// test.kt:8 foo
-// EXPECTATIONS JVM JVM_IR
 // test.kt:11 foo
 // test.kt:14 foo
-// EXPECTATIONS JVM
-// test.kt:15 foo
-// test.kt:17 foo
-// EXPECTATIONS JVM JVM_IR
 // test.kt:20 foo
 // test.kt:14 foo
 // test.kt:23 foo