[FIR] KT-56769: Ensure @receiver: is only allowed on receivers

Note that there's no code that checks that
FirReceiverParameter's annotation's use-site target
is indeed `@receiver:`, because otherwise the
annotation wouldn't have made it into
the FirReceiverParameter.

In contrast, in K1 all such annotations are treated
as annotations on a KtTypeReference.

^KT-56769 Fixed

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java

@@ -519,6 +519,12 @@ public class FirLightTreeOldFrontendDiagnosticsTestGenerated extends AbstractFir
             runTest("compiler/testData/diagnostics/tests/kt56723.kt");
         }
 
+        @Test
+        @TestMetadata("kt56769.kt")
+        public void testKt56769() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/kt56769.kt");
+        }
+
         @Test
         @TestMetadata("LValueAssignment.kt")
         public void testLValueAssignment() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java

@@ -519,6 +519,12 @@ public class FirPsiOldFrontendDiagnosticsTestGenerated extends AbstractFirPsiDia
             runTest("compiler/testData/diagnostics/tests/kt56723.kt");
         }
 
+        @Test
+        @TestMetadata("kt56769.kt")
+        public void testKt56769() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/kt56769.kt");
+        }
+
         @Test
         @TestMetadata("LValueAssignment.kt")
         public void testLValueAssignment() throws Exception {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/type/FirTypeAnnotationChecker.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.analysis.checkers.type
 
 import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.diagnostics.reportOn
@@ -24,10 +25,19 @@ object FirTypeAnnotationChecker : FirTypeRefChecker() {
 
         for (annotation in typeRef.annotations) {
             if (annotation.source == null) continue
+            val useSiteTarget = annotation.useSiteTarget
+
+            // Annotations with `@receiver:` go
+            // into FirReceiverParameter, not FirTypeRef
+            if (useSiteTarget == AnnotationUseSiteTarget.RECEIVER) {
+                reporter.reportOn(
+                    annotation.source, FirErrors.WRONG_ANNOTATION_TARGET_WITH_USE_SITE_TARGET,
+                    "type usage", useSiteTarget.renderName, context
+                )
+            }
 
             val annotationTargets = annotation.getAllowedAnnotationTargets(context.session)
             if (KotlinTarget.TYPE !in annotationTargets) {
-                val useSiteTarget = annotation.useSiteTarget
                 if (useSiteTarget == null || KotlinTarget.USE_SITE_MAPPING[useSiteTarget] !in annotationTargets) {
                     reporter.reportOn(annotation.source, FirErrors.WRONG_ANNOTATION_TARGET, "type usage", context)
                 }