JVM IR: generate private @JvmStatic functions as in old backend

#KT-46181 Fixed

compiler/testData/codegen/bytecodeListing/jvmStatic/jvmStaticExternal.kt

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+// JVM_TARGET: 1.8
+
+object TestObject {
+    @JvmStatic
+    external fun foo()
+}
+
+class TestClassCompanion {
+    companion object {
+        @JvmStatic
+        external fun foo()
+    }
+}