KT-14258 Optimize accesses to properties defined into companion

- Use direct access to property defined into companion object when
it is possible rather than always use an accessor to access the
property.
- Use direct access will speedup runtime performance.
- Avoid to generate useless accessors for companion properties.

Fix of https://youtrack.jetbrains.com/issue/KT-14258

compiler/testData/codegen/bytecodeText/companion/kt14258_5.kt

@@ -0,0 +1,19 @@
+// Checks that accessor are not used because property can be accessed directly.
+
+interface I {
+    companion object {
+        private var bar = "Companion Field from I"
+
+        fun test(): String {
+            bar = "New value"
+            return bar
+        }
+    }
+}
+
+// 1 GETSTATIC I\$Companion.bar
+// 2 PUTSTATIC I\$Companion.bar
+// 0 INVOKESTATIC I\$Companion.access\$getBar\$p
+// 0 INVOKESTATIC I\$Companion.access\$setBar\$cp
+// 0 INVOKESPECIAL I\$Companion.getBar
+// 0 INVOKESPECIAL I\$Companion.setBar