Add test for sdl2_ttf to test_other.py. NFC (#16125)

It seems that harfbuzz is not buildable on MacOS but we missed this
because it was only getting built as part of browser tests which only
run on linux (at least in CI they only run on linux).

See #16097, #16073

Author: sbc100

tests/test_other.py

@@ -1849,6 +1849,10 @@ def test_icu(self):
     self.set_setting('USE_ICU')
     self.do_runf(test_file('other/test_icu.cpp'))
 
+  def test_sdl2_ttf(self):
+    # This is a compile-only to test to verify that sdl2-ttf (and freetype and harfbuzz) are buildable.
+    self.emcc(test_file('sdl2_ttf.c'), args=['-sUSE_SDL=2', '-sUSE_SDL_TTF=2'], output_filename='a.out.js')
+
   def test_link_memcpy(self):
     # memcpy can show up *after* optimizations, so after our opportunity to link in libc, so it must be special-cased
     create_file('main.cpp', r'''