Condition code blocks over Coq/OCaml versions

[liyishuai]

Description of the problem

Some code works with certain versions of Coq and OCaml. To write Coq code that work with multiple versions, current solutions use cppo:

SimpleIO

#if OCAML_VERSION >= (4, 8, 0)
Extract Inlined Constant int_of_ascii => "Stdlib.int_of_char".
Extract Inlined Constant ascii_of_int => "Stdlib.char_of_int".
#else
Extract Inlined Constant int_of_ascii => "Pervasives.int_of_char".
Extract Inlined Constant ascii_of_int => "Pervasives.char_of_int".
#endif

QuickChick

#if COQ_VERSION >= (8, 15, 0)
Require Import ExtrOcamlZBigInt.
#else
Require Import ExtrOcamlZInt.
#endif

These code work fine in non-interactive scenarios (edit-save-preprocess-compile). Is it worth having similar functionality in Coqtop, so that these code can work with CoqIDE/ProofGeneral?