Convert size() functions in builtins to properties

Just like it will work itself out :)

compiler/testData/builtin-classes.txt

@@ -272,11 +272,12 @@ public interface Cloneable {
 }
 
 public interface Collection</*0*/ out E> : kotlin.Iterable<E> {
+    public abstract val size: kotlin.Int
+        public abstract fun <get-size>(): kotlin.Int
     public abstract operator fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
     public abstract fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
     public abstract fun isEmpty(): kotlin.Boolean
     public abstract override /*1*/ fun iterator(): kotlin.Iterator<E>
-    public abstract fun size(): kotlin.Int
 }
 
 public interface Comparable</*0*/ in T> {
@@ -744,6 +745,8 @@ public interface Iterator</*0*/ out T> {
 }
 
 public interface List</*0*/ out E> : kotlin.Collection<E> {
+    public abstract override /*1*/ val size: kotlin.Int
+        public abstract override /*1*/ fun <get-size>(): kotlin.Int
     public abstract override /*1*/ fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
     public abstract override /*1*/ fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
     public abstract operator fun get(/*0*/ index: kotlin.Int): E
@@ -753,7 +756,6 @@ public interface List</*0*/ out E> : kotlin.Collection<E> {
     public abstract fun lastIndexOf(/*0*/ o: kotlin.Any?): kotlin.Int
     public abstract fun listIterator(): kotlin.ListIterator<E>
     public abstract fun listIterator(/*0*/ index: kotlin.Int): kotlin.ListIterator<E>
-    public abstract override /*1*/ fun size(): kotlin.Int
     public abstract fun subList(/*0*/ fromIndex: kotlin.Int, /*1*/ toIndex: kotlin.Int): kotlin.List<E>
 }
 
@@ -903,13 +905,14 @@ public final class LongRange : kotlin.Range<kotlin.Long>, kotlin.Progression<kot
 }
 
 public interface Map</*0*/ K, /*1*/ out V> {
+    public abstract val size: kotlin.Int
+        public abstract fun <get-size>(): kotlin.Int
     public abstract fun containsKey(/*0*/ key: kotlin.Any?): kotlin.Boolean
     public abstract fun containsValue(/*0*/ value: kotlin.Any?): kotlin.Boolean
     public abstract fun entrySet(): kotlin.Set<kotlin.Map.Entry<K, V>>
     public abstract operator fun get(/*0*/ key: kotlin.Any?): V?
     public abstract fun isEmpty(): kotlin.Boolean
     public abstract fun keySet(): kotlin.Set<K>
-    public abstract fun size(): kotlin.Int
     public abstract fun values(): kotlin.Collection<V>
 
     public interface Entry</*0*/ out K, /*1*/ out V> {
@@ -919,6 +922,8 @@ public interface Map</*0*/ K, /*1*/ out V> {
 }
 
 public interface MutableCollection</*0*/ E> : kotlin.Collection<E>, kotlin.MutableIterable<E> {
+    public abstract override /*1*/ /*fake_override*/ val size: kotlin.Int
+        public abstract override /*1*/ /*fake_override*/ fun <get-size>(): kotlin.Int
     public abstract fun add(/*0*/ e: E): kotlin.Boolean
     public abstract fun addAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract fun clear(): kotlin.Unit
@@ -929,7 +934,6 @@ public interface MutableCollection</*0*/ E> : kotlin.Collection<E>, kotlin.Mutab
     public abstract fun remove(/*0*/ o: kotlin.Any?): kotlin.Boolean
     public abstract fun removeAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
     public abstract fun retainAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
-    public abstract override /*1*/ /*fake_override*/ fun size(): kotlin.Int
 }
 
 public interface MutableIterable</*0*/ out T> : kotlin.Iterable<T> {
@@ -943,6 +947,8 @@ public interface MutableIterator</*0*/ out T> : kotlin.Iterator<T> {
 }
 
 public interface MutableList</*0*/ E> : kotlin.List<E>, kotlin.MutableCollection<E> {
+    public abstract override /*2*/ /*fake_override*/ val size: kotlin.Int
+        public abstract override /*2*/ /*fake_override*/ fun <get-size>(): kotlin.Int
     public abstract override /*1*/ fun add(/*0*/ e: E): kotlin.Boolean
     public abstract fun add(/*0*/ index: kotlin.Int, /*1*/ element: E): kotlin.Unit
     public abstract override /*1*/ fun addAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
@@ -962,7 +968,6 @@ public interface MutableList</*0*/ E> : kotlin.List<E>, kotlin.MutableCollection
     public abstract override /*1*/ fun removeAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
     public abstract override /*1*/ fun retainAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
     public abstract operator fun set(/*0*/ index: kotlin.Int, /*1*/ element: E): E
-    public abstract override /*2*/ /*fake_override*/ fun size(): kotlin.Int
     public abstract override /*1*/ fun subList(/*0*/ fromIndex: kotlin.Int, /*1*/ toIndex: kotlin.Int): kotlin.MutableList<E>
 }
 
@@ -979,6 +984,8 @@ public interface MutableListIterator</*0*/ T> : kotlin.ListIterator<T>, kotlin.M
 }
 
 public interface MutableMap</*0*/ K, /*1*/ V> : kotlin.Map<K, V> {
+    public abstract override /*1*/ /*fake_override*/ val size: kotlin.Int
+        public abstract override /*1*/ /*fake_override*/ fun <get-size>(): kotlin.Int
     public abstract fun clear(): kotlin.Unit
     public abstract override /*1*/ /*fake_override*/ fun containsKey(/*0*/ key: kotlin.Any?): kotlin.Boolean
     public abstract override /*1*/ /*fake_override*/ fun containsValue(/*0*/ value: kotlin.Any?): kotlin.Boolean
@@ -989,7 +996,6 @@ public interface MutableMap</*0*/ K, /*1*/ V> : kotlin.Map<K, V> {
     public abstract fun put(/*0*/ key: K, /*1*/ value: V): V?
     public abstract fun putAll(/*0*/ m: kotlin.Map<out K, V>): kotlin.Unit
     public abstract fun remove(/*0*/ key: kotlin.Any?): V?
-    public abstract override /*1*/ /*fake_override*/ fun size(): kotlin.Int
     public abstract override /*1*/ fun values(): kotlin.MutableCollection<V>
 
     public interface MutableEntry</*0*/ K, /*1*/ V> : kotlin.Map.Entry<K, V> {
@@ -1000,6 +1006,8 @@ public interface MutableMap</*0*/ K, /*1*/ V> : kotlin.Map<K, V> {
 }
 
 public interface MutableSet</*0*/ E> : kotlin.Set<E>, kotlin.MutableCollection<E> {
+    public abstract override /*2*/ /*fake_override*/ val size: kotlin.Int
+        public abstract override /*2*/ /*fake_override*/ fun <get-size>(): kotlin.Int
     public abstract override /*1*/ fun add(/*0*/ e: E): kotlin.Boolean
     public abstract override /*1*/ fun addAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract override /*1*/ fun clear(): kotlin.Unit
@@ -1010,7 +1018,6 @@ public interface MutableSet</*0*/ E> : kotlin.Set<E>, kotlin.MutableCollection<E
     public abstract override /*1*/ fun remove(/*0*/ o: kotlin.Any?): kotlin.Boolean
     public abstract override /*1*/ fun removeAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
     public abstract override /*1*/ fun retainAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
-    public abstract override /*2*/ /*fake_override*/ fun size(): kotlin.Int
 }
 
 public final class Nothing {
@@ -1069,11 +1076,12 @@ public interface Range</*0*/ T : kotlin.Comparable<T>> {
 }
 
 public interface Set</*0*/ out E> : kotlin.Collection<E> {
+    public abstract override /*1*/ val size: kotlin.Int
+        public abstract override /*1*/ fun <get-size>(): kotlin.Int
     public abstract override /*1*/ fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
     public abstract override /*1*/ fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
     public abstract override /*1*/ fun isEmpty(): kotlin.Boolean
     public abstract override /*1*/ fun iterator(): kotlin.Iterator<E>
-    public abstract override /*1*/ fun size(): kotlin.Int
 }
 
 public final class Short : kotlin.Number, kotlin.Comparable<kotlin.Short> {

core/builtins/native/kotlin/Collections.kt

@@ -49,7 +49,7 @@ public interface Collection<out E> : Iterable<E> {
     /**
      * Returns the size of the collection.
      */
-    public fun size(): Int
+    public val size: Int
 
     /**
      * Returns `true` if the collection is empty (contains no elements), `false` otherwise.
@@ -128,7 +128,7 @@ public interface MutableCollection<E> : Collection<E>, MutableIterable<E> {
  */
 public interface List<out E> : Collection<E> {
     // Query Operations
-    override fun size(): Int
+    override val size: Int
     override fun isEmpty(): Boolean
     override fun contains(o: Any?): Boolean
     override fun iterator(): Iterator<E>
@@ -232,7 +232,7 @@ public interface MutableList<E> : List<E>, MutableCollection<E> {
  */
 public interface Set<out E> : Collection<E> {
     // Query Operations
-    override fun size(): Int
+    override val size: Int
     override fun isEmpty(): Boolean
     override fun contains(o: Any?): Boolean
     override fun iterator(): Iterator<E>
@@ -274,7 +274,7 @@ public interface Map<K, out V> {
     /**
      * Returns the number of key/value pairs in the map.
      */
-    public fun size(): Int
+    public val size: Int
 
     /**
      * Returns `true` if the map is empty (contains no elements), `false` otherwise.