[Bug libfortran/90374] Fortran 2018: Support d0.d, e0.d, es0.d, en0.d, g0.d and ew.d e0 edit descriptors for output

[thenlich at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90374

--- Comment #35 from Thomas Henlich <thenlich at gcc dot gnu.org> ---
I tried to investigate the next issue:

  write (aresult,fmt="(G0.10e0)") rn
  if (aresult /= "0.3139999928E-2") stop 52

triggers "E specifier not allowed with g0 descriptor in format string" during
compilation. But it is allowed, according to F2018.

The following works as it should:
  afmt = "(G0.10e0)"
  write (aresult,fmt=afmt) rn
  if (aresult /= "0.3139999928E-2") stop 33

That is how far I got. Probably some changes are required in io.c
(check_format)