[JVM_IR] Rebase inline function and defaults args stepping test.

compiler/testData/debug/stepping/simpleInlineDefaultArg.kt

@@ -1,5 +1,5 @@
-// IGNORE_BACKEND: JVM_IR
 // FILE: test.kt
+
 inline fun alsoInline() = "OK"
 
 inline fun ifoo(s: String = alsoInline()): String {
@@ -10,9 +10,29 @@ fun box(): String {
     return ifoo()
 }
 
+// `alsoInline` is inlined in the `ifoo$default` stub. When exiting the inline
+// codegen, the line number is reset. Therefore any code generated with line
+// number information will emit a new line number so that stepping continues
+// in the caller.
+//
+// For JVM none of the code after `alsoInline` leads to line number generation.
+// This seems problematic as the line number for the inline function is then
+// in effect for instructions outside the scope of the `$i$f$alsoInline`
+// variable life time.
+//
+// For JVM_IR a line number is generated for the code following `alsoInline`.
+// Therefore, we stop on line 5 before entering `alsoInline`
+// and we step back to line 5 after `alsoInline` and before the body of
+// `ifoo`. This seems reasonable and also help ensure that line numbers
+// for the inline function are only used for instructions covered by
+// the `$i$f$alsoInline` variable life time.
+
 // LINENUMBERS
 // test.kt:10 box
 // test.kt:5 box
 // test.kt:3 box
+// LINENUMBERS JVM_IR
+// test.kt:5 box
+// LINENUMBERS
 // test.kt:6 box
 // test.kt:10 box