Don't report incompatibility expect/actual errors on usual overloads

Divide incompatibility on two groups: strong and weak. Strong incompatibility means that if declaration with such incompatibility has no `actual` modifier then it's considered as usual overload and we'll not report any error on it.

 #KT-20540 Fixed
 #KT-20680 Fixed

compiler/testData/diagnostics/tests/multiplatform/headerClass/actualClassWithDefaultValuesInAnnotationViaTypealias.txt

@@ -42,6 +42,13 @@ public final expect annotation class Foo6 : kotlin.Annotation {
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public final expect annotation class Foo7 : kotlin.Annotation {
+    public constructor Foo7()
+    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
+}
+
 
 // -- Module: <m2-jvm> --
 package
@@ -89,5 +96,14 @@ public final actual annotation class Foo5 : kotlin.Annotation {
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
+
+public final actual annotation class Foo6 : kotlin.Annotation {
+    public constructor Foo6(/*0*/ s: kotlin.String = ...)
+    public final val s: kotlin.String
+    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 typealias Foo1 = Bar1
 public typealias Foo4 = Bar2
+public typealias Foo7 = Bar2

compiler/testData/diagnostics/tests/multiplatform/headerClass/actualClassWithDifferentConstructors.kt

@@ -9,6 +9,8 @@ expect class Foo3
 expect class Bar1()
 expect class Bar2()
 expect class Bar3()
+expect class Bar4()
+expect class Bar5()
 
 // MODULE: m2-jvm(m1-common)
 
@@ -30,6 +32,14 @@ actual class Foo1(val s: String)
 actual class Foo2(val p: String = "value", <!UNUSED_PARAMETER!>i<!>: Int)
 actual typealias Foo3 = JavaFoo
 
-actual class Bar1<!ACTUAL_WITHOUT_EXPECT!>(val s: String)<!>
-actual class Bar2<!ACTUAL_WITHOUT_EXPECT!>(val p: String = "value", <!UNUSED_PARAMETER!>i<!>: Int)<!>
-<!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>actual typealias Bar3 = JavaBar<!>
+actual class <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>Bar1<!>(val s: String)
+actual class <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>Bar2<!>(val p: String = "value", <!UNUSED_PARAMETER!>i<!>: Int)
+actual typealias <!NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS!>Bar3<!> = JavaBar
+actual class Bar4(val s: String) {
+    <!ACTUAL_MISSING!>constructor() : this("")<!>
+}
+
+actual class Bar5 {
+    actual constructor()
+    constructor(s: String)
+}

compiler/testData/diagnostics/tests/multiplatform/headerClass/actualClassWithDifferentConstructors.txt

@@ -22,6 +22,20 @@ public final expect class Bar3 {
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public final expect class Bar4 {
+    public constructor Bar4()
+    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 expect class Bar5 {
+    public constructor Bar5()
+    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 expect class Foo1 {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
@@ -60,6 +74,23 @@ public final actual class Bar2 {
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public final actual class Bar4 {
+    public constructor Bar4()
+    public constructor Bar4(/*0*/ s: kotlin.String)
+    public final val s: kotlin.String
+    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 actual class Bar5 {
+    public constructor Bar5()
+    public constructor Bar5(/*0*/ s: kotlin.String)
+    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 actual class Foo1 {
     public constructor Foo1(/*0*/ s: kotlin.String)
     public final val s: kotlin.String

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithStrongIncompatibilities.kt

@@ -0,0 +1,27 @@
+// !LANGUAGE: +MultiPlatformProjects
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// MODULE: m1-common
+// FILE: common.kt
+
+expect fun foo1(x: Int)
+expect fun foo2<!JVM:NO_ACTUAL_FOR_EXPECT!>(x: Int)<!>
+
+expect class NoArgConstructor()
+
+// MODULE: m2-jvm(m1-common)
+
+// FILE: jvm.kt
+
+actual fun foo1(x: Int) {}
+
+fun foo1(x: Int, y: Int) {}
+fun foo1(x: String) {}
+
+fun foo2(x: Int, y: Int) {}
+fun foo2(x: String) {}
+
+actual class NoArgConstructor {
+    actual constructor()
+    actual constructor<!ACTUAL_WITHOUT_EXPECT!>(x: Int)<!>
+    constructor(x: String)
+}

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithStrongIncompatibilities.txt

@@ -0,0 +1,31 @@
+// -- Module: <m1-common> --
+package
+
+public expect fun foo1(/*0*/ x: kotlin.Int): kotlin.Unit
+public expect fun foo2(/*0*/ x: kotlin.Int): kotlin.Unit
+
+public final expect class NoArgConstructor {
+    public constructor NoArgConstructor()
+    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
+}
+
+
+// -- Module: <m2-jvm> --
+package
+
+public actual fun foo1(/*0*/ x: kotlin.Int): kotlin.Unit
+public fun foo1(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.Int): kotlin.Unit
+public fun foo1(/*0*/ x: kotlin.String): kotlin.Unit
+public fun foo2(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.Int): kotlin.Unit
+public fun foo2(/*0*/ x: kotlin.String): kotlin.Unit
+
+public final actual class NoArgConstructor {
+    public constructor NoArgConstructor()
+    public constructor NoArgConstructor(/*0*/ x: kotlin.Int)
+    public constructor NoArgConstructor(/*0*/ x: kotlin.String)
+    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/multiplatform/headerClass/expectDeclarationWithWeakIncompatibilities.kt

@@ -0,0 +1,23 @@
+// !LANGUAGE: +MultiPlatformProjects
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// MODULE: m1-common
+// FILE: common.kt
+
+expect class Foo1
+expect class Foo2
+
+expect fun foo1(): Int
+expect fun foo2(): Int
+expect fun foo3<!JVM:NO_ACTUAL_FOR_EXPECT!>()<!>: Int
+
+// MODULE: m2-jvm(m1-common)
+
+// FILE: jvm.kt
+
+<!ACTUAL_WITHOUT_EXPECT!>interface<!> Foo1
+actual <!ACTUAL_WITHOUT_EXPECT!>interface<!> Foo2
+
+actual fun foo1(): <!ACTUAL_WITHOUT_EXPECT!>String<!> = ""
+
+fun <!ACTUAL_MISSING!>foo2<!>(): Int = 0
+fun foo3(x: Int): String = ""

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithWeakIncompatibilities.txt

@@ -0,0 +1,38 @@
+// -- Module: <m1-common> --
+package
+
+public expect fun foo1(): kotlin.Int
+public expect fun foo2(): kotlin.Int
+public expect fun foo3(): kotlin.Int
+
+public final expect class Foo1 {
+    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 expect class Foo2 {
+    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
+}
+
+
+// -- Module: <m2-jvm> --
+package
+
+public actual fun foo1(): kotlin.String
+public fun foo2(): kotlin.Int
+public fun foo3(/*0*/ x: kotlin.Int): kotlin.String
+
+public interface Foo1 {
+    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 actual interface Foo2 {
+    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/multiplatform/topLevelFun/valueParameterModifiers.kt

@@ -11,8 +11,8 @@ expect fun f4(s: () -> String)
 expect inline fun f5(s: () -> String)
 expect inline fun f6(crossinline s: () -> String)
 
-expect fun f7(x: Any)
-expect fun f8(vararg x: Any)
+expect fun f7<!JVM:NO_ACTUAL_FOR_EXPECT!>(x: Any)<!>
+expect fun f8<!JVM:NO_ACTUAL_FOR_EXPECT!>(vararg x: Any)<!>
 
 // MODULE: m2-jvm(m1-common)
 // FILE: jvm.kt