Re: avoid creating sys/time.h replacement when possible

[Bruno Haible]

Jim Meyering wrote:
>   - use $(SYS_TIME_H) also in the definition of MOSTLYCLEANFILES

This is not a good change. Suppose a user does in the same directory
  - first, a "./configure; make" for a deficient platform,
  - then, a "./configure" for a glibc platform
  - then he notices that he forgot to "make distclean" first, so he does
    "make distclean",
  - then, again, "./configure; make" for the glibc platform.

The generated .h file from the first build will stick around and cause
continuous trouble.

That's the reason why

  alloca-opt
  argz
  ...
  wchar
  wctype

all have the .h file _unconditionally_ in the MOSTLYCLEANFILES.

Bruno