[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/plusMatrix.sig.kt.txt

@@ -0,0 +1,34 @@
+// CHECK:
+//   Mangled name: Matrix
+//   Public signature: /Matrix|null[0]
+class Matrix {
+  // CHECK:
+  //   Mangled name: Matrix#<init>(){}
+  //   Public signature: /Matrix.<init>|-5645683436151566731[0]
+  constructor() /* primary */
+
+}
+
+// CHECK:
+//   Mangled name: NumberOperations
+//   Public signature: /NumberOperations|null[0]
+interface NumberOperations {
+
+  // CHECK JVM_IR:
+  //   Mangled name: NumberOperations#plus@kotlin.Number(kotlin.Number){}kotlin.Number
+  //   Public signature: /NumberOperations.plus|-6518987633126930952[0]
+  abstract fun Number.plus(other: Number): Number
+
+}
+
+// CHECK JVM_IR:
+//   Mangled name computed from Ir:         #plus@Matrix(NumberOperations;Matrix){}Matrix
+//   Mangled name computed from Descriptor: #plus!NumberOperations@Matrix(Matrix){}Matrix
+//   Public signature: /plus|1303343764214809933[0]
+fun Matrix.plus($context_receiver_0: NumberOperations, other: Matrix): Matrix
+
+// CHECK:
+//   Mangled name: #plusMatrix@NumberOperations(Matrix;Matrix){}
+//   Public signature: /plusMatrix|-8194087590203252948[0]
+fun NumberOperations.plusMatrix(m1: Matrix, m2: Matrix): Unit
+