[klib] Test signature descriptions in irText tests

KT-59486

compiler/testData/ir/irText/expressions/funInterface/castFromAny.sig.kt.txt

@@ -6,6 +6,7 @@ fun interface KRunnable {
   // CHECK:
   //   Mangled name: KRunnable#invoke(){}
   //   Public signature: /KRunnable.invoke|-4663091332620260873[0]
+  //   Public signature debug description: invoke(){}
   abstract fun invoke(): Unit
 
 }
@@ -13,5 +14,6 @@ fun interface KRunnable {
 // CHECK:
 //   Mangled name: #test(kotlin.Any?){}
 //   Public signature: /test|4942271194395271693[0]
+//   Public signature debug description: test(kotlin.Any?){}
 fun test(a: Any?): Unit