Test that both NFC and NFD input produces identical results for fonts
that used composed fonts internally (Amiri here) and fonts that
decompose internally (Noto Nastaliq Urdu here) and that for the former
composed forms are used.
See https://github.com/harfbuzz/harfbuzz/issues/3179
No idea why test names are underscorified but it it just makes calling
meson test testname harder than it should being not able to copy file
name directly.
Khaled Hosny
Behdad Esfahbod