Tests: add FILE directives to some multimodule tests

To help them run on the old infrastructure, which light analysis tests
are still using.

compiler/testData/codegen/box/annotations/suppressInvisibleMember.kt

@@ -2,6 +2,8 @@
 // ISSUE: KT-55026
 
 // MODULE: lib
+// FILE: lib.kt
+
 interface Base {
     val x: String
 }
@@ -10,6 +12,8 @@ internal class Some(override val x: String) : Base
 internal class Other(override val x: String) : Base
 
 // MODULE: main(lib)
+// FILE: main.kt
+
 @file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
 
 internal fun Some(): Base = Some("K")