[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/js/native/nativeNativeKotlin.kt.txt

@@ -1,13 +1,13 @@
 package foo
 
 open external class A {
-  external constructor() /* primary */ 
+  external constructor() /* primary */
   external fun foo(): String
 
 }
 
 open external class B : A {
-  external constructor() /* primary */ 
+  external constructor() /* primary */
   external fun bar(): String
 
 }

compiler/testData/ir/irText/js/native/nativeNativeKotlin.sig.kt.txt

@@ -0,0 +1,64 @@
+package foo
+
+// CHECK:
+//   Mangled name: foo.A
+//   Public signature: foo/A|null[0]
+open external class A {
+  // CHECK:
+  //   Mangled name: foo.A#<init>(){}
+  //   Public signature: foo/A.<init>|-5645683436151566731[0]
+  external constructor() /* primary */
+
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: foo.A#foo(){}
+  //   Public signature: foo/A.foo|-1041209573719867811[0]
+  external fun foo(): String
+
+}
+
+// CHECK:
+//   Mangled name: foo.B
+//   Public signature: foo/B|null[0]
+open external class B : A {
+  // CHECK:
+  //   Mangled name: foo.B#<init>(){}
+  //   Public signature: foo/B.<init>|-5645683436151566731[0]
+  external constructor() /* primary */
+
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: foo.B#foo(){}
+  //   Public signature: foo/B.foo|-1041209573719867811[0]
+  external /* fake */ override fun foo(): String
+
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: foo.B#bar(){}
+  //   Public signature: foo/B.bar|496682602797471549[0]
+  external fun bar(): String
+
+}
+
+// CHECK:
+//   Mangled name: foo.C
+//   Public signature: foo/C|null[0]
+class C : B {
+  // CHECK:
+  //   Mangled name: foo.C#<init>(){}
+  //   Public signature: foo/C.<init>|-5645683436151566731[0]
+  constructor() /* primary */
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: foo.C#bar(){}
+  //   Public signature: foo/C.bar|496682602797471549[0]
+  /* fake */ override fun bar(): String
+
+  // CHECK JS_IR NATIVE:
+  //   Mangled name: foo.C#foo(){}
+  //   Public signature: foo/C.foo|-1041209573719867811[0]
+  /* fake */ override fun foo(): String
+
+}
+
+// CHECK JS_IR NATIVE:
+//   Mangled name: foo#box(){}
+//   Public signature: foo/box|2173511048851971368[0]
+fun box(): String
+