Move substitution override unwrapping to FirVisibilityChecker

This is because it is only needed for the declaration itself, not for
the containing class. Currently there is no difference because
`containingNonLocalClass` will look at the dispatch receiver argument if
one exists anyway, and for substitution/intersection overrides one must
exist.

compiler/fir/providers/src/org/jetbrains/kotlin/fir/FirVisibilityChecker.kt

@@ -87,7 +87,7 @@ abstract class FirVisibilityChecker : FirSessionComponent {
         supertypeSupplier: SupertypeSupplier = SupertypeSupplier.Default
     ): Boolean {
         if (!isSpecificDeclarationVisible(
-                declaration,
+                if (declaration is FirCallableDeclaration) declaration.originalOrSelf() else declaration,
                 session,
                 useSiteFile,
                 containingDeclarations,

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/VisibilityUtils.kt

@@ -28,27 +28,16 @@ fun FirVisibilityChecker.isVisible(
     declaration: FirMemberDeclaration,
     callInfo: CallInfo,
     dispatchReceiverValue: ReceiverValue?
-): Boolean {
-    if (declaration is FirCallableDeclaration && (declaration.isIntersectionOverride || declaration.isSubstitutionOverride)) {
-        @Suppress("UNCHECKED_CAST")
-        return isVisible(declaration.originalIfFakeOverride() as FirMemberDeclaration, callInfo, dispatchReceiverValue)
-    }
-
-    val useSiteFile = callInfo.containingFile
-    val containingDeclarations = callInfo.containingDeclarations
-    val session = callInfo.session
-
-    return isVisible(
+): Boolean =
+    isVisible(
         declaration,
-        session,
-        useSiteFile,
-        containingDeclarations,
+        callInfo.session,
+        callInfo.containingFile,
+        callInfo.containingDeclarations,
         dispatchReceiverValue,
         callInfo.callSite is FirVariableAssignment
     )
 
-}
-
 fun FirVisibilityChecker.isVisible(
     declaration: FirMemberDeclaration,
     candidate: Candidate
@@ -66,14 +55,7 @@ fun FirVisibilityChecker.isVisible(
 
     val backingField = declaration.getBackingFieldIfApplicable()
     if (backingField != null) {
-        candidate.hasVisibleBackingField = isVisible(
-            backingField,
-            callInfo.session,
-            callInfo.containingFile,
-            callInfo.containingDeclarations,
-            candidate.dispatchReceiverValue,
-            candidate.callInfo.callSite is FirVariableAssignment,
-        )
+        candidate.hasVisibleBackingField = isVisible(backingField, callInfo, candidate.dispatchReceiverValue)
     }
 
     return true