KT-5488 Invalid ambiguity between plus and plusAssign

#KT-5488  Fixed

compiler/testData/diagnostics/tests/operatorsOverloading/AssignOperatorAmbiguity.kt

@@ -8,7 +8,7 @@ class MyInt(val i: Int) {
 fun Any.plusAssign(<!UNUSED_PARAMETER!>a<!>: Any) {}
 
 fun test(m: MyInt) {
-    m <!ASSIGN_OPERATOR_AMBIGUITY!>+=<!> m
+    m += m
 
     var i = 1
     i <!ASSIGN_OPERATOR_AMBIGUITY!>+=<!> 34

compiler/testData/diagnostics/tests/operatorsOverloading/plusAssignOnArray.kt

@@ -0,0 +1,20 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+class C {
+    fun get(i: Int): C = this
+}
+
+fun C.plus(a: Any): C = this
+fun C.plusAssign(a: Any) {}
+
+class C1 {
+    fun get(i: Int): C = C()
+    fun set(i: Int, v: C) {}
+}
+
+fun test() {
+    val c = C()
+    c[0] += ""
+    var c1 = C1()
+    c1[0] <!ASSIGN_OPERATOR_AMBIGUITY!>+=<!> ""
+}

compiler/testData/diagnostics/tests/operatorsOverloading/plusAssignOnArray.txt

@@ -0,0 +1,22 @@
+package
+
+internal fun test(): kotlin.Unit
+internal fun C.plus(/*0*/ a: kotlin.Any): C
+internal fun C.plusAssign(/*0*/ a: kotlin.Any): kotlin.Unit
+
+internal final class C {
+    public constructor C()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun get(/*0*/ i: kotlin.Int): C
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class C1 {
+    public constructor C1()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun get(/*0*/ i: kotlin.Int): C
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun set(/*0*/ i: kotlin.Int, /*1*/ v: C): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/operatorsOverloading/plusAssignOnLocal.kt

@@ -0,0 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+class C
+
+fun C.plus(a: Any): C = this
+fun C.plusAssign(a: Any) {}
+
+fun test() {
+    val c = C()
+    c += ""
+    var c1 = C()
+    c1 <!ASSIGN_OPERATOR_AMBIGUITY!>+=<!> ""
+}

compiler/testData/diagnostics/tests/operatorsOverloading/plusAssignOnLocal.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun test(): kotlin.Unit
+internal fun C.plus(/*0*/ a: kotlin.Any): C
+internal fun C.plusAssign(/*0*/ a: kotlin.Any): kotlin.Unit
+
+internal final class C {
+    public constructor C()
+    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
+}

compiler/testData/diagnostics/tests/operatorsOverloading/plusAssignOnProperty.kt

@@ -0,0 +1,19 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+class C {
+    val c: C = C()
+}
+
+fun C.plus(a: Any): C = this
+fun C.plusAssign(a: Any) {}
+
+class C1 {
+    var c: C = C()
+}
+
+fun test() {
+    val c = C()
+    c.c += ""
+    var c1 = C1()
+    c1.c <!ASSIGN_OPERATOR_AMBIGUITY!>+=<!> ""
+}

compiler/testData/diagnostics/tests/operatorsOverloading/plusAssignOnProperty.txt

@@ -0,0 +1,21 @@
+package
+
+internal fun test(): kotlin.Unit
+internal fun C.plus(/*0*/ a: kotlin.Any): C
+internal fun C.plusAssign(/*0*/ a: kotlin.Any): kotlin.Unit
+
+internal final class C {
+    public constructor C()
+    internal final val c: C
+    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
+}
+
+internal final class C1 {
+    public constructor C1()
+    internal final var c: C
+    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
+}