Support nullable callable references in FIR resolve

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/FirResolvedQualifier.kt

@@ -25,6 +25,7 @@ abstract class FirResolvedQualifier : FirPureAbstractElement(), FirExpression {
     abstract val packageFqName: FqName
     abstract val relativeClassFqName: FqName?
     abstract val classId: ClassId?
+    abstract val safe: Boolean
     abstract val typeArguments: List<FirTypeProjection>
 
     override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitResolvedQualifier(this, data)

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirResolvedQualifierImpl.kt

@@ -24,7 +24,8 @@ import org.jetbrains.kotlin.fir.visitors.*
 class FirResolvedQualifierImpl(
     override val source: FirSourceElement?,
     override var packageFqName: FqName,
-    override var relativeClassFqName: FqName?
+    override var relativeClassFqName: FqName?,
+    override var safe: Boolean
 ) : FirResolvedQualifier(), FirAbstractAnnotatedElement {
     override var typeRef: FirTypeRef = FirImplicitTypeRefImpl(null)
     override val annotations: MutableList<FirAnnotationCall> = mutableListOf()

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt

@@ -944,7 +944,7 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
     override fun visitCallableReferenceAccess(callableReferenceAccess: FirCallableReferenceAccess) {
         callableReferenceAccess.annotations.renderAnnotations()
         callableReferenceAccess.explicitReceiver?.accept(this)
-        if (callableReferenceAccess.safe) {
+        if (callableReferenceAccess.safe && callableReferenceAccess.explicitReceiver !is FirResolvedQualifier) {
             print("?")
         }
         print("::")
@@ -1052,6 +1052,9 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
         } else {
             print(resolvedQualifier.packageFqName.asString().replace(".", "/"))
         }
+        if (resolvedQualifier.safe) {
+            print("?")
+        }
         print("|")
     }
 

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

@@ -323,7 +323,7 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
         }
 
         impl(resolvedQualifier) {
-            isMutable("packageFqName", "relativeClassFqName")
+            isMutable("packageFqName", "relativeClassFqName", "safe")
             default("classId") {
                 value = """
                     |relativeClassFqName?.let {

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

@@ -435,6 +435,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
             +field("packageFqName", fqNameType)
             +field("relativeClassFqName", fqNameType, nullable = true)
             +field("classId", classIdType, nullable = true)
+            +booleanField("safe")
             +typeArguments.withTransform()
         }