Compile FreeType with pthreads support (#16546)

Expects the runtime will support atomic access, even in single-threaded
mode. See WebAssembly/threads#144 for more.

tests/test_other.py

@@ -1860,6 +1860,10 @@ def test_freetype(self):
                      '   ****     ****'
     self.assertContained(expectedOutput, self.run_process(config.JS_ENGINES[0] + ['a.out.js'], stdout=PIPE, stderr=PIPE).stdout)
 
+  def test_freetype_with_pthreads(self):
+    # Verify that freetype supports compilation requiring pthreads
+    self.emcc(test_file('freetype_test.c'), ['-sUSE_PTHREADS', '-sUSE_FREETYPE'], output_filename='a.out.js')
+
   def test_icu(self):
     self.set_setting('USE_ICU')
     self.do_runf(test_file('other/test_icu.cpp'))

tools/ports/freetype.py

@@ -98,7 +98,8 @@ def create(final):
                        '-I' + dest_path + '/psaux',
                        '-I' + dest_path + '/psnames',
                        '-I' + dest_path + '/truetype',
-                       '-w'])
+                       '-w',
+                       '-pthread'])
       o_s.append(o)
 
     ports.run_commands(commands)