FIR: fix infinite recursion with equality operator checker

compiler/testData/diagnostics/tests/RecursiveTypeParameterEqualityCheck.fir.kt

@@ -0,0 +1,9 @@
+interface Foo<out T>
+interface Bar1 : Foo<Bar1>
+interface Bar2 : Foo<Bar2>
+class Bar3 : Foo<Bar3>
+
+fun test(b1: Bar1, b2: Bar2, b3: Bar3) {
+    b1 == b2
+    <!EQUALITY_NOT_APPLICABLE_WARNING!>b1 == b3<!>
+}

compiler/testData/diagnostics/tests/RecursiveTypeParameterEqualityCheck.kt

@@ -0,0 +1,9 @@
+interface Foo<out T>
+interface Bar1 : Foo<Bar1>
+interface Bar2 : Foo<Bar2>
+class Bar3 : Foo<Bar3>
+
+fun test(b1: Bar1, b2: Bar2, b3: Bar3) {
+    b1 == b2
+    <!EQUALITY_NOT_APPLICABLE!>b1 == b3<!>
+}

compiler/testData/diagnostics/tests/RecursiveTypeParameterEqualityCheck.txt

@@ -0,0 +1,28 @@
+package
+
+public fun test(/*0*/ b1: Bar1, /*1*/ b2: Bar2, /*2*/ b3: Bar3): kotlin.Unit
+
+public interface Bar1 : Foo<Bar1> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface Bar2 : Foo<Bar2> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Bar3 : Foo<Bar3> {
+    public constructor Bar3()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface Foo</*0*/ out T> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}