Usage: meson-pgo.sh auto|partial|full <source-dir> <build-dir> <meson-options>
Note: build-dir must *not* exist before the script is run (but if it
does, the script will tell you so, and exit).
Supported compilers: gcc and clang
The script does *not* add _any_ custom meson options, except configure
-Db_pgo. Thus, you probably want to call it like this:
meson-pgo.sh auto . /tmp/foot-pgo-build --buildtype=release -Db_lto=true
