Check class source in bytecode listing tests

compiler/testData/codegen/kapt/interfaceImpls.txt

@@ -1,11 +1,13 @@
 @kotlin.Metadata
 public final class A$DefaultImpls {
+    // source: 'interfaceImpls.kt'
     public static method a(@org.jetbrains.annotations.NotNull p0: A): void
     public final inner class A$DefaultImpls
 }
 
 @kotlin.Metadata
 public interface A {
+    // source: 'interfaceImpls.kt'
     public abstract method a(): void
     public abstract method b(): void
     public final inner class A$DefaultImpls
@@ -13,5 +15,6 @@ public interface A {
 
 @kotlin.Metadata
 public interface B {
+    // source: 'interfaceImpls.kt'
     public abstract method b(): void
 }