[K/Wasm] Introduce stepping tests for Wasm

compiler/testData/debug/stepping/commentBeforeFunctionWithDefault.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND: WASM
 // FILE: test.kt
 
 // Comment before
@@ -10,11 +11,11 @@ fun box() {
 }
 
 // EXPECTATIONS JVM JVM_IR
-// test.kt:9 box
-// test.kt:5 foo
-// test.kt:9 box
 // test.kt:10 box
+// test.kt:6 foo
+// test.kt:10 box
+// test.kt:11 box
 
 // EXPECTATIONS JS_IR
-// test.kt:9 box
 // test.kt:10 box
+// test.kt:11 box