[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/funInterface/samConversionInVarargs.sig.kt.txt

@@ -0,0 +1,40 @@
+// CHECK:
+//   Mangled name: IFoo
+//   Public signature: /IFoo|null[0]
+fun interface IFoo {
+
+  // CHECK:
+  //   Mangled name: IFoo#foo(kotlin.Int){}
+  //   Public signature: /IFoo.foo|-104159190164110731[0]
+  abstract fun foo(i: Int): Unit
+
+}
+
+// CHECK:
+//   Mangled name: #testAdaptedCR(){}
+//   Public signature: /testAdaptedCR|-2000726175248606[0]
+fun testAdaptedCR(): Unit
+
+// CHECK:
+//   Mangled name: #testLambda(){}
+//   Public signature: /testLambda|-124997257399938843[0]
+fun testLambda(): Unit
+
+// CHECK:
+//   Mangled name: #testSeveralLambdas(){}
+//   Public signature: /testSeveralLambdas|884186753581284332[0]
+fun testSeveralLambdas(): Unit
+
+// CHECK:
+//   Mangled name: #useVararg(kotlin.Array<out|IFoo>...){}
+//   Public signature: /useVararg|-167843892719966590[0]
+fun useVararg(vararg foos: IFoo): Unit
+
+// CHECK JVM_IR:
+//   Mangled name: #withVarargOfInt(kotlin.IntArray...){}kotlin.String
+//   Public signature: /withVarargOfInt|-4664776409518571139[0]
+// CHECK JS_IR NATIVE:
+//   Mangled name: #withVarargOfInt(kotlin.IntArray...){}
+//   Public signature: /withVarargOfInt|-232972314185863621[0]
+fun withVarargOfInt(vararg xs: Int): String
+