meson: drop broken split-usr handling

Two issues here:

* The 'split-usr' meson option wasn't doing anything, it tried to check
  if /bin was a symlink, but nothing acted on this information.

* The actual rootprefix default was decided based on whether /bin was a symlink
  which is flaky if e.g. building on a merged-usr system for use on a non-merged-usr
  system.

There's no real advantage to installing to /usr over / as the compat. symlinks
are really here to stay. If someone really does care about this, they can bring
it back and do it properly, but it doesn't seem worth it to me at all.

Bug: https://bugs.gentoo.org/927776
Signed-off-by: Sam James <[email protected]>

meson.build

@@ -83,14 +83,8 @@ else
   pkg_prefix = option_pkg_prefix
 endif
 
-if get_option('split-usr') == 'auto'
-  split_usr = run_command('test', '-L', '/bin', check: false).returncode() != 0
-else
-  split_usr = get_option('split-usr') == 'true'
-endif
-
 rootprefix = get_option('rootprefix')
-rootprefix_default = fs.is_symlink('/bin') ? '/usr' : '/'
+rootprefix_default = '/'
 if rootprefix == ''
 rootprefix = rootprefix_default
 endif

meson_options.txt

@@ -26,9 +26,6 @@ option('selinux', type : 'feature', value : 'auto',
   description : 'enable SELinux support')
 option('shell', type : 'string', value : '/bin/sh',
   description : 'Default posix compatible shell')
-option('split-usr', type : 'combo',
-  choices : ['auto', 'true', 'false'],
-  description : '''/bin, /sbin aren't symlinks into /usr''')
 option('sysvinit', type : 'boolean', value : false,
   description : 'enable SysVinit compatibility (linux only)')
 option('termcap', type : 'combo',