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_4.kt

@@ -0,0 +1,23 @@
+// Checks that accessor 'I$Companion.access$getBar\$p' is always used because the property is kept
+// into the companion object.
+
+interface I {
+    companion object {
+        private var bar = "Companion Field from I"
+    }
+
+    fun test(): String {
+        // INVOKESTATIC I$Companion.access$setBar$p
+        bar = "New value"
+        // INVOKESTATIC I$Companion.access$getBar$p
+        return bar
+    }
+}
+
+// 1 GETSTATIC I\$Companion.bar
+// 2 PUTSTATIC I\$Companion.bar
+// 1 INVOKESTATIC I\$Companion.access\$getBar\$p
+// 1 INVOKESTATIC I\$Companion.access\$setBar\$p
+// 0 INVOKESTATIC I\$Companion.access\$setBar\$cp
+// 0 INVOKESPECIAL I\$Companion.getBar
+// 0 INVOKESPECIAL I\$Companion.setBar