JVM IR: slightly change field renaming convention implementation

Prefer to rename fields from the class, not from the companion, to be
more in line with the old backend's behavior. This has no effect on the
behavior of current tests but removes differences in metadata (since
metadata has information about every property->field mapping) in some of
them

compiler/testData/writeFlags/property/classObject/rename/delegatedAndDelegated.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 import kotlin.reflect.KProperty
 
 public open class TestDelegate<T: Any>(private val initializer: () -> T) {