[IR] Dump IdSignatures and mangled names in irText tests

The reason #1 for this feature is that we want to test IdSignatures
generated for declarations. Currently, there is no (easy) way to ensure
that a change in the signature building logic doesn't cause any breaking
changes wrt klibs.

Now, most IdSignatures include hashed mangled names in them, so even if
we catch a regression where the included hash changes, there would be no
way of knowing immediately what caused it, unless we'd also have mangled
names in the expectations.

The reason #2 is to test the manglers themselves. Currently, there are
no tests for them. They heavily duplicate each other, this is already
causing issues (see KT-57427) that would be very hard to catch without
these tests.

^KT-58238 Fixed

compiler/testData/ir/irText/expressions/temporaryInInitBlock.sig.kt.txt

@@ -0,0 +1,23 @@
+// CHECK:
+//   Mangled name: C
+//   Public signature: /C|null[0]
+class C {
+  // CHECK:
+  //   Mangled name: C{}s
+  //   Public signature: /C.s|7217541905509134881[0]
+  val s: String?
+    // CHECK JVM_IR:
+    //   Mangled name: C#<get-s>(){}kotlin.String?
+    //   Public signature: /C.s.<get-s>|-8914674600070030279[0]
+    // CHECK JS_IR NATIVE:
+    //   Mangled name: C#<get-s>(){}
+    //   Public signature: /C.s.<get-s>|-1662172381559511151[0]
+    get
+
+  // CHECK:
+  //   Mangled name: C#<init>(kotlin.Any?){}
+  //   Public signature: /C.<init>|-8205545948568413246[0]
+  constructor(x: Any?) /* primary */
+
+}
+