Drop TypeUsage::MEMBER_SIGNATURE_COVARIANT

It's only used for choosing mutability of a collection class, but
using annotations while loading is redundant since there is
a separate phase of type enhancement where they're taken
into account (for flexible types)

For inflexible type it doesn't matter since they appear only in
special cases like annotation methods (where collection classes can't be met)

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/components/TypeUsage.java

@@ -21,7 +21,6 @@ package org.jetbrains.kotlin.load.java.components;
  * This enum encodes the kinds of occurrences
  */
 public enum TypeUsage {
-    MEMBER_SIGNATURE_COVARIANT,
     MEMBER_SIGNATURE_CONTRAVARIANT,
     SUPERTYPE,
     COMMON

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaScope.kt

@@ -146,7 +146,7 @@ abstract class LazyJavaScope(protected val c: LazyJavaResolverContext) : MemberS
     protected fun computeMethodReturnType(method: JavaMethod, annotations: Annotations, c: LazyJavaResolverContext): KotlinType {
         val annotationMethod = method.containingClass.isAnnotationType
         val returnTypeAttrs = LazyJavaTypeAttributes(
-                TypeUsage.MEMBER_SIGNATURE_COVARIANT, annotations,
+                TypeUsage.COMMON, annotations,
                 allowFlexible = !annotationMethod,
                 isForAnnotationParameter = annotationMethod
         )

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/types/JavaTypeResolver.kt

@@ -22,7 +22,8 @@ import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.annotations.CompositeAnnotations
 import org.jetbrains.kotlin.descriptors.annotations.FilteredAnnotations
 import org.jetbrains.kotlin.load.java.ANNOTATIONS_COPIED_TO_TYPES
-import org.jetbrains.kotlin.load.java.JvmAnnotationNames.*
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames.JETBRAINS_NOT_NULL_ANNOTATION
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames.JETBRAINS_NULLABLE_ANNOTATION
 import org.jetbrains.kotlin.load.java.components.TypeUsage
 import org.jetbrains.kotlin.load.java.components.TypeUsage.*
 import org.jetbrains.kotlin.load.java.lazy.LazyJavaAnnotations
@@ -150,24 +151,12 @@ class JavaTypeResolver(
 
         val javaToKotlin = JavaToKotlinClassMap
 
-        val howThisTypeIsUsedEffectively = when {
-            attr.flexibility == FLEXIBLE_LOWER_BOUND -> MEMBER_SIGNATURE_COVARIANT
-            attr.flexibility == FLEXIBLE_UPPER_BOUND -> MEMBER_SIGNATURE_CONTRAVARIANT
-
-            // This case has to be checked before isMarkedReadOnly/isMarkedMutable, because those two are slow
-            // not mapped, we don't care about being marked mutable/read-only
-            !javaToKotlin.isJavaPlatformClass(fqName) -> attr.howThisTypeIsUsed
-
-            // Read (possibly external) annotations
-            else -> attr.howThisTypeIsUsedAccordingToAnnotations
-        }
-
         val kotlinDescriptor = javaToKotlin.mapJavaToKotlin(fqName, c.module.builtIns) ?: return null
 
         if (javaToKotlin.isReadOnly(kotlinDescriptor)) {
-            if (howThisTypeIsUsedEffectively == MEMBER_SIGNATURE_COVARIANT
-                || howThisTypeIsUsedEffectively == SUPERTYPE
-                || javaType.argumentsMakeSenseOnlyForMutableContainer(readOnlyContainer = kotlinDescriptor)) {
+            if (attr.flexibility == FLEXIBLE_LOWER_BOUND ||
+                attr.howThisTypeIsUsed == SUPERTYPE ||
+                javaType.argumentsMakeSenseOnlyForMutableContainer(readOnlyContainer = kotlinDescriptor)) {
                 return javaToKotlin.convertReadOnlyToMutable(kotlinDescriptor)
             }
         }
@@ -293,7 +282,6 @@ internal fun makeStarProjection(
 
 interface JavaTypeAttributes {
     val howThisTypeIsUsed: TypeUsage
-    val howThisTypeIsUsedAccordingToAnnotations: TypeUsage
     val isMarkedNotNull: Boolean
     val flexibility: JavaTypeFlexibility
         get() = INFLEXIBLE
@@ -328,16 +316,7 @@ class LazyJavaTypeAttributes(
         override val isForAnnotationParameter: Boolean = false
 ): JavaTypeAttributes {
     override val typeAnnotations = FilteredAnnotations(annotations) { it in ANNOTATIONS_COPIED_TO_TYPES }
-
-    override val howThisTypeIsUsedAccordingToAnnotations: TypeUsage get() =
-            if (hasAnnotation(JETBRAINS_READONLY_ANNOTATION) && !hasAnnotation(JETBRAINS_MUTABLE_ANNOTATION))
-                TypeUsage.MEMBER_SIGNATURE_CONTRAVARIANT
-            else
-                TypeUsage.MEMBER_SIGNATURE_COVARIANT
-
     override val isMarkedNotNull: Boolean get() = typeAnnotations.isMarkedNotNull()
-
-    private fun hasAnnotation(fqName: FqName) = typeAnnotations.findAnnotation(fqName) != null
 }
 
 fun Annotations.isMarkedNotNull() = findAnnotation(JETBRAINS_NOT_NULL_ANNOTATION) != null
@@ -349,8 +328,6 @@ fun TypeUsage.toAttributes(
         upperBoundForTypeParameter: TypeParameterDescriptor? = null
 ) = object : JavaTypeAttributes {
     override val howThisTypeIsUsed: TypeUsage = this@toAttributes
-    override val howThisTypeIsUsedAccordingToAnnotations: TypeUsage
-            get() = howThisTypeIsUsed
     override val isMarkedNotNull: Boolean = false
     override val allowFlexible: Boolean = allowFlexible