[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/declarations/contextReceivers/function.sig.kt.txt

@@ -0,0 +1,35 @@
+// CHECK:
+//   Mangled name: C
+//   Public signature: /C|null[0]
+class C {
+  // CHECK:
+  //   Mangled name: C{}c
+  //   Public signature: /C.c|-4416962153448040627[0]
+  val c: Int
+    field
+    // CHECK JVM_IR:
+    //   Mangled name: C#<get-c>(){}kotlin.Int
+    //   Public signature: /C.c.<get-c>|-2440337234483931882[0]
+    get
+
+  // CHECK:
+  //   Mangled name: C#<init>(){}
+  //   Public signature: /C.<init>|-5645683436151566731[0]
+  constructor() /* primary */
+
+}
+
+// CHECK:
+//   Mangled name: #bar(C){}
+//   Public signature: /bar|-380723744805794672[0]
+fun bar(c: C): Unit
+  // CHECK:
+  //   Mangled name: #bar(C){}#<anonymous>#static@C(){}
+  local fun C.<anonymous>(): Unit
+
+// CHECK:
+//   Mangled name computed from Ir:         #foo(C){}
+//   Mangled name computed from Descriptor: #foo!C(){}
+//   Public signature: /foo|-1491377105373055541[0]
+fun foo($context_receiver_0: C): Unit
+