[FE, IR] Store PsiElement for mismatched annotation's actual target

There is IDE quick fix which suggests to copy mismatched annotation
from `expect` to `actual` (see KTIJ-26633). It needs to find
`actual` PsiElement where to add annotation. Before previous commit, it
was easy - just get source of `Incompatibility.actualSymbol`.
After previous commit, the problem might be in value parameter, while
`actualSymbol` would contain function symbol. This is solved by adding
new field `Incompatibility.actualAnnotationTargetElement`.

`SourceElementMarker` introduced, because it's needed to be used in
abstract checker. Existing `DeclarationSymbolMarker` doesn't fit
because in next PR for this issue annotations set on types will be reported,
and types are not declarations.

^KT-60671

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/actualizer/IrExpectActualMatchingContext.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.calls.mpp.ExpectActualCollectionArgumentsCompatibilityCheckStrategy
 import org.jetbrains.kotlin.resolve.calls.mpp.ExpectActualMatchingContext
 import org.jetbrains.kotlin.resolve.calls.mpp.ExpectActualMatchingContext.AnnotationCallInfo
+import org.jetbrains.kotlin.mpp.SourceElementMarker
 import org.jetbrains.kotlin.resolve.checkers.OptInNames
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility
 import org.jetbrains.kotlin.types.AbstractTypeChecker
@@ -523,4 +524,9 @@ internal abstract class IrExpectActualMatchingContext(
         actualMember: DeclarationSymbolMarker,
         checkClassScopesCompatibility: Boolean,
     ): Map<out DeclarationSymbolMarker, ExpectActualCompatibility<*>> = error("Should not be called")
+
+    // It's a stub, because not needed anywhere
+    private object IrSourceElementStub : SourceElementMarker
+
+    override fun DeclarationSymbolMarker.getSourceElement(): SourceElementMarker = IrSourceElementStub
 }