[FIR] KT-56877: Allow checking types of containing classes in contracts

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/contracts/ConeEffectExtractor.kt

@@ -9,11 +9,9 @@ import org.jetbrains.kotlin.contracts.description.EventOccurrencesRange
 import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.contracts.description.*
-import org.jetbrains.kotlin.fir.declarations.FirContractDescriptionOwner
-import org.jetbrains.kotlin.fir.declarations.FirDeclaration
-import org.jetbrains.kotlin.fir.declarations.FirProperty
-import org.jetbrains.kotlin.fir.declarations.FirValueParameter
+import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.expressions.*
+import org.jetbrains.kotlin.fir.resolve.getContainingClass
 import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.fir.types.coneType
 import org.jetbrains.kotlin.fir.visitors.FirDefaultVisitor
@@ -156,7 +154,10 @@ class ConeEffectExtractor(
         data: Nothing?
     ): ConeContractDescriptionElement? {
         val declaration = thisReceiverExpression.calleeReference.boundSymbol?.fir ?: return null
-        return if (declaration == owner || owner.isAccessorOf(declaration)) {
+        val callableOwner = owner as? FirCallableDeclaration
+        val ownerHasReceiver = callableOwner?.receiverParameter != null
+        val ownerIsMemberOfDeclaration = callableOwner?.getContainingClass(session) == declaration
+        return if (declaration == owner || owner.isAccessorOf(declaration) || ownerIsMemberOfDeclaration && !ownerHasReceiver) {
             val type = thisReceiverExpression.typeRef.coneType
             toValueParameterReference(type, -1, "this")
         } else {

compiler/testData/diagnostics/tests/kt56877.fir.kt

@@ -9,7 +9,7 @@ open class Result {
 
     fun isSuccess1(): Boolean {
         contract {
-            <!ERROR_IN_CONTRACT_DESCRIPTION!>returns(true) implies (this@Result is Success)<!>
+            returns(true) implies (this@Result is Success)
         }
         return this@Result is Success
     }

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/errors/accessToOuterThis.fir.kt

@@ -10,7 +10,7 @@ class Foo {
     inner class Bar {
         fun good() {
             contract {
-                <!ERROR_IN_CONTRACT_DESCRIPTION!>returns() implies (this@Bar != null)<!>
+                returns() implies (this@Bar != null)
             }
         }