Overridden functions using default arguments in recursive call are no more considered tail recursive #KT-4285 Fixed

compiler/testData/diagnostics/tests/tailRecOverridden.kt

@@ -0,0 +1,32 @@
+// See also KT-4285
+open class A {
+    open fun foo(x: Int = 0) {}
+
+    open fun gav(y: Int = 1, z: Int = 2) {}
+}
+
+class B: A() {
+    <!NO_TAIL_CALLS_FOUND!>tailrec override fun foo(x: Int)<!> {
+        foo()
+    }
+
+    <!NO_TAIL_CALLS_FOUND!>tailrec override fun gav(y: Int, z: Int)<!> {
+        gav(y)
+    }
+
+    tailrec fun bar(y: Double): Double = bar(y * 2.0)
+}
+
+class C: A() {
+    tailrec override fun foo(x: Int) {
+        foo(0)
+    }
+
+    tailrec override fun gav(y: Int, z: Int) {
+        gav(y - 1, z - 1)
+    }
+
+    tailrec fun bar(<!UNUSED_PARAMETER!>y<!>: Int = 1, z: Int = 2) {
+        bar(z)
+    }
+}

compiler/testData/diagnostics/tests/tailRecOverridden.txt

@@ -0,0 +1,30 @@
+package
+
+public open class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(/*0*/ x: kotlin.Int = ...): kotlin.Unit
+    public open fun gav(/*0*/ y: kotlin.Int = ..., /*1*/ z: kotlin.Int = ...): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class B : A {
+    public constructor B()
+    public final tailrec fun bar(/*0*/ y: kotlin.Double): kotlin.Double
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open tailrec override /*1*/ fun foo(/*0*/ x: kotlin.Int = ...): kotlin.Unit
+    public open tailrec override /*1*/ fun gav(/*0*/ y: kotlin.Int = ..., /*1*/ z: kotlin.Int = ...): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class C : A {
+    public constructor C()
+    public final tailrec fun bar(/*0*/ y: kotlin.Int = ..., /*1*/ z: kotlin.Int = ...): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open tailrec override /*1*/ fun foo(/*0*/ x: kotlin.Int = ...): kotlin.Unit
+    public open tailrec override /*1*/ fun gav(/*0*/ y: kotlin.Int = ..., /*1*/ z: kotlin.Int = ...): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}