Allow enum entries in double colon LHS with LV = 1.0

#KT-16782 Fixed

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

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.codeFragmentUtil.suppressDiagnosticsInDebugMode
+import org.jetbrains.kotlin.psi.psiUtil.getTopmostParentQualifiedExpressionForSelector
 import org.jetbrains.kotlin.resolve.calls.CallExpressionElement
 import org.jetbrains.kotlin.resolve.calls.unrollToLeftMostQualifiedExpression
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
@@ -119,7 +120,10 @@ class QualifiedExpressionResolver {
 
     private fun checkNotEnumEntry(descriptor: DeclarationDescriptor?, trace: BindingTrace, expression: KtSimpleNameExpression) {
         if (descriptor != null && DescriptorUtils.isEnumEntry(descriptor)) {
-            trace.report(Errors.ENUM_ENTRY_AS_TYPE.on(expression))
+            val qualifiedParent = expression.getTopmostParentQualifiedExpressionForSelector()
+            if (qualifiedParent == null || qualifiedParent.parent !is KtDoubleColonExpression) {
+                trace.report(Errors.ENUM_ENTRY_AS_TYPE.on(expression))
+            }
         }
     }
 

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DoubleColonExpressionResolver.kt

@@ -423,7 +423,9 @@ class DoubleColonExpressionResolver(
                 val classDescriptor = resultingDescriptor.classDescriptor
                 if (classDescriptor.companionObjectDescriptor != null) return null
 
-                if (DescriptorUtils.isObject(classDescriptor)) {
+                if (DescriptorUtils.isObject(classDescriptor) ||
+                    (!languageVersionSettings.supportsFeature(LanguageFeature.BoundCallableReferences) &&
+                     DescriptorUtils.isEnumEntry(classDescriptor))) {
                     return DoubleColonLHS.Expression(typeInfo, isObjectQualifier = true)
                 }
             }

compiler/testData/diagnostics/tests/sourceCompatibility/noBoundCallableReferences/boundCallableReference.kt

@@ -13,6 +13,11 @@ val fail2 = <!UNSUPPORTED_FEATURE!>O<!>::hashCode
 val ok2 = O::Y
 val ok3 = O.Y::hashCode
 
+enum class E {
+    Entry
+}
+val ok4 = E.Entry::hashCode
+
 fun hashCode() {}
 
 val fail3 = <!UNSUPPORTED_FEATURE!>""<!>::hashCode

compiler/testData/diagnostics/tests/sourceCompatibility/noBoundCallableReferences/boundCallableReference.txt

@@ -8,6 +8,7 @@ public val fail5: kotlin.reflect.KFunction0<kotlin.Int>
 public val ok1: kotlin.reflect.KFunction1<C, kotlin.Int>
 public val ok2: kotlin.reflect.KFunction0<O.Y>
 public val ok3: kotlin.reflect.KFunction1<O.Y, kotlin.Int>
+public val ok4: kotlin.reflect.KFunction1<E.Entry, kotlin.Int>
 public fun hashCode(): kotlin.Unit
 
 public final class C {
@@ -24,6 +25,25 @@ public final class C {
     }
 }
 
+public final enum class E : kotlin.Enum<E> {
+    enum entry Entry
+
+    private constructor E()
+    public final override /*1*/ /*fake_override*/ val name: kotlin.String
+    public final override /*1*/ /*fake_override*/ val ordinal: kotlin.Int
+    protected final override /*1*/ /*fake_override*/ fun clone(): kotlin.Any
+    public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: E): kotlin.Int
+    public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    protected/*protected and package*/ final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun finalize(): kotlin.Unit
+    public final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun getDeclaringClass(): java.lang.Class<E!>!
+    public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): E
+    public final /*synthesized*/ fun values(): kotlin.Array<E>
+}
+
 public object O {
     private constructor O()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean

compiler/testData/diagnostics/tests/sourceCompatibility/noBoundCallableReferences/boundClassLiteral.kt

@@ -7,6 +7,10 @@ val ok2 = C.Companion::class
 object O
 val ok3 = O::class
 
+enum class E {
+    Entry
+}
+val ok4 = E.Entry::class
 
 val fail1 = <!UNSUPPORTED_FEATURE!>""<!>::class
 val fail2 = <!NULLABLE_TYPE_IN_CLASS_LITERAL_LHS!>String?::class<!>

compiler/testData/diagnostics/tests/sourceCompatibility/noBoundCallableReferences/boundClassLiteral.txt

@@ -7,6 +7,7 @@ public val fail4: kotlin.reflect.KClass<out C.Companion>
 public val ok1: kotlin.reflect.KClass<C>
 public val ok2: kotlin.reflect.KClass<C.Companion>
 public val ok3: kotlin.reflect.KClass<O>
+public val ok4: kotlin.reflect.KClass<E.Entry>
 
 public final class C {
     public constructor C()
@@ -22,6 +23,25 @@ public final class C {
     }
 }
 
+public final enum class E : kotlin.Enum<E> {
+    enum entry Entry
+
+    private constructor E()
+    public final override /*1*/ /*fake_override*/ val name: kotlin.String
+    public final override /*1*/ /*fake_override*/ val ordinal: kotlin.Int
+    protected final override /*1*/ /*fake_override*/ fun clone(): kotlin.Any
+    public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: E): kotlin.Int
+    public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    protected/*protected and package*/ final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun finalize(): kotlin.Unit
+    public final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun getDeclaringClass(): java.lang.Class<E!>!
+    public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): E
+    public final /*synthesized*/ fun values(): kotlin.Array<E>
+}
+
 public object O {
     private constructor O()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean