[coreutils] considering uncrustify for automatic indentation: prepare

[Jim Meyering]

  [PATCH 1/4] stat: use gnulib's alignof module
  [PATCH 2/4] maint: correct indentation of case_GETOPT_* macro uses
  [PATCH 3/4] maint: replace each "for (;;)" with "while (true)"
  [PATCH 4/4] maint: make spacing around "=" consistent, even in IF_LINT

I've been considering using uncrustify to automatically
format coreutils, and have begun addressing some of the
issues that exposed.  For example, it doesn't handle the
syntactically unrecognizable case_GETOPT_* macros, so
I have a manual post-processing step that "outdents"
them to make them align with other "case" statements.
Some were over-indented.

uncrustify mis-handled the sole alignof #define, so I've
removed that in favor of using the gnulib module.

Rather than try to make an exception to an exception to
the spacing-in-degenerate-for-statement rule, I've simply
replaced all of them with "while (true)" or "while (1)".

Finally, I've made changes like this:

  -  struct stat *stats IF_LINT (= 0);
  +  struct stat *stats IF_LINT ( = 0);

so that uncrustify doesn't need to know that this "=" is
somehow different from all others.