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/codegen/box/fieldRename/jvmFieldNoClash2.kt

@@ -1,5 +1,8 @@
 // TARGET_BACKEND: JVM
 // WITH_RUNTIME
+// FULL_JDK
+
+import java.lang.reflect.Modifier
 
 class A {
     val x = "outer"
@@ -19,5 +22,11 @@ fun box(): String {
     if (A.x != "companion") return "Fail companion x"
     if (A.y != "companion") return "Fail companion y"
 
+    if (!Modifier.isStatic(A::class.java.getDeclaredField("x").modifiers))
+        return "Fail: A.x should be static"
+
+    if (Modifier.isStatic(A::class.java.getDeclaredField("x$1").modifiers))
+        return "Fail: A.x$1 should not be static"
+
     return "OK"
 }