[IR] Make IrGetObjectValue copyable to avoid duplicate IR nodes.

Fixes KT-45170

compiler/testData/codegen/box/objects/kt45170.kt

@@ -0,0 +1,10 @@
+object A {
+    var id = 0
+        get() = field.also { field++ }
+}
+
+fun box(): String {
+    if (A.id != 0) return "FAIL1"
+    if (A.id != 1) return "FAIL2"
+    return "OK"
+}