More systematic m4 quoting and indentation.

More systematic m4 quoting and indentation.

* m4/chdir-long.m4 (gl_FUNC_CHDIR_LONG): Quote systematically.
* m4/d-ino.m4 (gl_CHECK_TYPE_STRUCT_DIRENT_D_INO): Likewise.
* m4/d-type.m4 (gl_CHECK_TYPE_STRUCT_DIRENT_D_TYPE): Likewise.
* m4/dirfd.m4 (gl_FUNC_DIRFD): Likewise.
* m4/host-os.m4 (gl_HOST_OS): Likewise.
* m4/jm-winsz1.m4 (gl_HEADER_TIOCGWINSZ_IN_TERMIOS_H,
gl_WINSIZE_IN_PTEM): Likewise.
* m4/mbrtowc.m4 (AC_FUNC_MBRTOWC): Likewise.
* m4/physmem.m4 (gl_SYS__SYSTEM_CONFIGURATION): Likewise.
* m4/pselect.m4 (gl_FUNC_PSELECT): Likewise.
* m4/fchownat.m4 (gl_FUNC_FCHOWNAT_DEREF_BUG): Quote systematically.
Correct indentation.
* m4/getcwd-abort-bug.m4 (gl_FUNC_GETCWD_ABORT_BUG): Likewise.
* m4/getcwd-path-max.m4 (gl_FUNC_GETCWD_PATH_MAX): Likewise.
* m4/jm-winsz2.m4 (gl_HEADER_TIOCGWINSZ_NEEDS_SYS_IOCTL): Likewise.
* m4/rmdir-errno.m4 (gl_FUNC_RMDIR_NOTEMPTY): Likewise.
* m4/tzset.m4 (gl_FUNC_TZSET_CLOBBER): Likewise.
* m4/unlink-busy.m4 (gl_FUNC_UNLINK_BUSY_TEXT): Likewise.