util: Introduce host-specific cpuinfo.h

The entire contents of the header is host-specific, but the
existence of such a header is not, which could prevent some
host specific ifdefs at the top of the file for the include.

Add host/include/{arch,generic} to the project arguments.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

host/include/generic/host/cpuinfo.h

@@ -0,0 +1,4 @@
+/*
+ * No host specific cpu indentification.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */

meson.build

@@ -512,6 +512,16 @@ add_project_arguments('-iquote', '.',
                       '-iquote', meson.current_source_dir() / 'include',
                       language: all_languages)
 
+# If a host-specific include directory exists, list that first...
+host_include = meson.current_source_dir() / 'host/include/'
+if fs.is_dir(host_include / host_arch)
+  add_project_arguments('-iquote', host_include / host_arch,
+                        language: all_languages)
+endif
+# ... followed by the generic fallback.
+add_project_arguments('-iquote', host_include / 'generic',
+                      language: all_languages)
+
 sparse = find_program('cgcc', required: get_option('sparse'))
 if sparse.found()
   run_target('sparse',