meson: upgrade to 1.8.0

meson: upgrade to 1.8.0

- New argument android_exe_type for executables
- Changes to the b_sanitize option
- New C standard c2y (and gnu2y)
- i18n module xgettext
- version_compare now accept multiple compare strings
- Improvements to Objective-C and Objective-C++
- Per project subproject options rewrite
- objects added correctly to Rust executables
- rust.test now supports link_whole
- Meson can run "rustdoc" on Rust projects
- The Wayland module is stable
- New swift_std compiler option
- New option to execute a slice of tests
- Valgrind now fails tests if errors are found

Full release notes: https://mesonbuild.com/Release-notes-for-1-8-0.html.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>