Don't print descriptors' toString() in diagnostic messages

Use DescriptorRenderer.TEXT instead, it doesn't print the debug information

idea/testData/diagnosticMessage/differentNamesForSameParameter.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS_NUMBER: 1
+// !DIAGNOSTICS: DIFFERENT_NAMES_FOR_THE_SAME_PARAMETER_IN_SUPERTYPES
+
+trait A {
+    fun foo(x: Int)
+}
+
+trait B {
+    fun foo(y: Int) {}
+}
+
+class differentNamesForSameParameter : A, B

idea/testData/diagnosticMessage/differentNamesForSameParameter1.txt

@@ -0,0 +1,2 @@
+<!-- differentNamesForSameParameter1 -->
+Names of the parameter #1 conflict in the following members of supertypes: 'internal abstract fun foo(x: kotlin.Int): kotlin.Unit defined in A, internal open fun foo(y: kotlin.Int): kotlin.Unit defined in B'. This may cause problems when calling this function with named arguments.

idea/testData/diagnosticMessage/extensionInClassReference.kt

@@ -0,0 +1,8 @@
+// !DIAGNOSTICS_NUMBER: 1
+// !DIAGNOSTICS: EXTENSION_IN_CLASS_REFERENCE_NOT_ALLOWED
+
+class extensionInClassReference {
+    fun Int.foo() {}
+
+    val bar = Int::foo
+}

idea/testData/diagnosticMessage/extensionInClassReference1.txt

@@ -0,0 +1,2 @@
+<!-- extensionInClassReference1 -->
+'foo' is a member and an extension at the same time. References to such elements are not allowed

idea/testData/diagnosticMessage/multipleDefaultsFromSupertypes.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS_NUMBER: 1
+// !DIAGNOSTICS: MULTIPLE_DEFAULTS_INHERITED_FROM_SUPERTYPES_WHEN_NO_EXPLICIT_OVERRIDE
+
+trait C {
+    fun foo(x: Int = 42)
+}
+
+trait D {
+    fun foo(x: Int = 239) {}
+}
+
+class multipleDefaultsFromSupertypes : C, D

idea/testData/diagnosticMessage/multipleDefaultsFromSupertypes1.txt

@@ -0,0 +1,2 @@
+<!-- multipleDefaultsFromSupertypes1 -->
+More than one overridden descriptor declares a default value for 'value-parameter val x: kotlin.Int = ... defined in multipleDefaultsFromSupertypes.foo'. As the compiler can not make sure these values agree, this is not allowed.

idea/testData/diagnosticMessage/unusedValue.kt

@@ -0,0 +1,8 @@
+// !DIAGNOSTICS_NUMBER: 1
+// !DIAGNOSTICS: UNUSED_VALUE
+
+fun unusedValue(): Int {
+    var x: Int
+    x = 239
+    return 42
+}

idea/testData/diagnosticMessage/unusedValue1.txt

@@ -0,0 +1,2 @@
+<!-- unusedValue1 -->
+The value '239' assigned to 'var x: kotlin.Int defined in unusedValue' is never used