[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/parameters/localFun.sig.kt.txt

@@ -0,0 +1,20 @@
+// CHECK:
+//   Mangled name: #outer(){0§<kotlin.Any?>}
+//   Public signature: /outer|-6093606212547620330[0]
+fun <TT : Any?> outer(): Unit
+  // CHECK:
+  //   Mangled name: #outer(){0§<kotlin.Any?>}#test1#static(kotlin.Int;0:0){0§<kotlin.Any?>}
+  local fun <T : Any?> test1(i: Int, j: T): Unit
+
+  // CHECK:
+  //   Mangled name: #outer(){0§<kotlin.Any?>}#test2#static(kotlin.Int;kotlin.String){}
+  local fun test2(i: Int, j: String): Unit
+
+  // CHECK:
+  //   Mangled name: #outer(){0§<kotlin.Any?>}#test3#static(kotlin.Array<out|kotlin.String>...){}
+  local fun test3(vararg args: String): Unit
+
+  // CHECK:
+  //   Mangled name: #outer(){0§<kotlin.Any?>}#textExt1#static@kotlin.String(kotlin.Int;1:0){}
+  local fun String.textExt1(i: Int, j: TT): Unit
+