Check for repeated annotations in type alias declaration.

compiler/frontend/src/org/jetbrains/kotlin/resolve/AnnotationChecker.kt

@@ -46,6 +46,9 @@ class AnnotationChecker(private val additionalCheckers: Iterable<AdditionalAnnot
             annotated.typeReference?.let { check(it, trace) }
             annotated.receiverTypeReference?.let { check(it, trace) }
         }
+        if (annotated is KtTypeAlias) {
+            annotated.getTypeReference()?.let { check(it, trace) }
+        }
         if (annotated is KtTypeParameterListOwner && annotated is KtCallableDeclaration) {
             // TODO: support type parameter annotations for type parameters on classes and properties
             annotated.typeParameters.forEach { check(it, trace) }

compiler/testData/diagnostics/tests/typealias/typealiasRhsRepeatedAnnotations.kt

@@ -0,0 +1,4 @@
+@Target(AnnotationTarget.TYPE)
+annotation class A
+
+typealias Test1 = @A <!REPEATED_ANNOTATION!>@A<!> Int

compiler/testData/diagnostics/tests/typealias/typealiasRhsRepeatedAnnotations.txt

@@ -0,0 +1,9 @@
+package
+
+@kotlin.annotation.Target(allowedTargets = {AnnotationTarget.TYPE}) public final annotation class A : kotlin.Annotation {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+public typealias Test1 = @A @A kotlin.Int

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -20910,6 +20910,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("typealiasRhsRepeatedAnnotations.kt")
+            public void testTypealiasRhsRepeatedAnnotations() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/typealiasRhsRepeatedAnnotations.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("unsupportedTypeAlias.kt")
             public void testUnsupportedTypeAlias() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/unsupportedTypeAlias.kt");