[FIR] Store expressions of receivers inside candidates instead of ReceiverValue

This is needed because of mutable nature of receiver values: implicit
  receiver values can be modified because of smartcasts, but in candidate
  we need to store snapshot of receiver in the form it was at the beginning
  of the resolution

^KT-58823 Fixed

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/FirThisReference.kt

@@ -20,6 +20,7 @@ abstract class FirThisReference : FirReference() {
     abstract val labelName: String?
     abstract val boundSymbol: FirBasedSymbol<*>?
     abstract val contextReceiverNumber: Int
+    abstract val isImplicit: Boolean
 
     override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitThisReference(this, data)
 

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirExplicitThisReference.kt

@@ -23,6 +23,7 @@ internal class FirExplicitThisReference(
     override var contextReceiverNumber: Int,
 ) : FirThisReference() {
     override var boundSymbol: FirBasedSymbol<*>? = null
+    override val isImplicit: Boolean = false
 
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/references/impl/FirImplicitThisReference.kt

@@ -23,6 +23,7 @@ internal class FirImplicitThisReference(
 ) : FirThisReference() {
     override val source: KtSourceElement? get() = null
     override val labelName: String? get() = null
+    override val isImplicit: Boolean = true
 
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
 

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/ImplementationConfigurator.kt

@@ -484,6 +484,7 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
                 value = "null"
                 isMutable = true
             }
+            defaultFalse("isImplicit")
         }
 
         impl(thisReference, "FirImplicitThisReference") {
@@ -495,6 +496,7 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
             default("boundSymbol") {
                 isMutable = false
             }
+            defaultTrue("isImplicit")
         }
 
         impl(superReference, "FirExplicitSuperReference")

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/NodeConfigurator.kt

@@ -687,6 +687,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
             +stringField("labelName", nullable = true)
             +field("boundSymbol", firBasedSymbolType, "*", nullable = true, withReplace = true)
             +intField("contextReceiverNumber", withReplace = true)
+            +booleanField("isImplicit")
         }
 
         typeRef.configure {