Cleanup

- do not use annotation resolve in CodegenFileClassProvider
- test using private methods across different parts of multifile class

compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithCrossPrivate/Baz.java

@@ -0,0 +1,5 @@
+public class Baz {
+    public static String baz() {
+        return Util.foo() + Util.bar();
+    }
+}

compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithCrossPrivate/bar.kt

@@ -0,0 +1,5 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun bar(): String = barx()
+
+private fun foox(): String = "O"

compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithCrossPrivate/foo.kt

@@ -0,0 +1,5 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun foo(): String = foox()
+
+private fun barx(): String = "K"

compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithCrossPrivate/multifileClassWithInternal.kt

@@ -0,0 +1 @@
+fun box(): String = Baz.baz()