Clean size/length/first/head/empty properties and functions.

libraries/stdlib/test/collections/ArraysJVMTest.kt

@@ -201,13 +201,13 @@ class ArraysJVMTest {
     test fun orEmptyNull() {
         val x: Array<String>? = null
         val xArray: Array<String> = x.orEmpty()
-        expect(0) { xArray.size }
+        expect(0) { xArray.size() }
     }
 
     test fun orEmptyNotNull() {
         val x: Array<String>? = array("1", "2")
         val xArray: Array<String> = x.orEmpty()
-        expect(2) { xArray.size }
+        expect(2) { xArray.size() }
         expect("1") { xArray[0] }
         expect("2") { xArray[1] }
     }