K1: introduce synthetic assignment checker with deprecation for KT-54305

#KT-54305 Fixed
Related to KT-54309

compiler/testData/diagnostics/tests/syntheticSet.kt

@@ -20,7 +20,7 @@ public class Wrapper<W> {
 
 fun foo(container: Container<*>, wrapper: Wrapper<String>) {
     container.w = <!TYPE_MISMATCH!>wrapper<!>
-    container.wrapper = wrapper
+    <!SYNTHETIC_SETTER_PROJECTED_OUT!>container.wrapper<!> = wrapper
     container.setWrapper(<!TYPE_MISMATCH!>wrapper<!>)
 }
 
@@ -42,16 +42,16 @@ fun dif(container: Container<String>, wrapper: Wrapper<Int>) {
 }
 
 fun out(container: Container<out Any>, wrapper: Wrapper<String>) {
-    container.wrapper = wrapper
+    <!SYNTHETIC_SETTER_PROJECTED_OUT!>container.wrapper<!> = wrapper
     container.setWrapper(<!TYPE_MISMATCH!>wrapper<!>)
 }
 
 fun inn(container: Container<in String>, wrapper: Wrapper<Any>) {
-    container.wrapper = wrapper
+    <!SYNTHETIC_SETTER_PROJECTED_OUT!>container.wrapper<!> = wrapper
     container.setWrapper(<!TYPE_MISMATCH!>wrapper<!>)
 }
 
 fun <T> generic(container: Container<out T>, wrapper: Wrapper<out T>) {
-    container.wrapper = wrapper
+    <!SYNTHETIC_SETTER_PROJECTED_OUT!>container.wrapper<!> = wrapper
     container.setWrapper(<!TYPE_MISMATCH!>wrapper<!>)
 }

compiler/testData/diagnostics/tests/syntheticSetFalsePositive.kt

@@ -0,0 +1,15 @@
+// FIR_IDENTICAL
+// FILE: JavaClass.java
+import java.util.List;
+
+public interface JavaClass<E> {
+    List<? extends E> getFoo();
+    void setFoo(List<? extends E> l);
+}
+
+// FILE: main.kt
+
+fun foo(x: JavaClass<in CharSequence>, l: MutableList<out CharSequence>) {
+    x.setFoo(l) // OK
+    x.foo = l // Should be OK, too
+}

compiler/testData/diagnostics/tests/syntheticSetFalsePositive.txt

@@ -0,0 +1,11 @@
+package
+
+public fun foo(/*0*/ x: JavaClass<in kotlin.CharSequence>, /*1*/ l: kotlin.collections.MutableList<out kotlin.CharSequence>): kotlin.Unit
+
+public interface JavaClass</*0*/ E : kotlin.Any!> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun getFoo(): (kotlin.collections.MutableList<out E!>..kotlin.collections.List<E!>?)
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun setFoo(/*0*/ l: (kotlin.collections.MutableList<out E!>..kotlin.collections.List<E!>?)): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}