nasm: Add -mms-bitfields to the list of ignored flags

Fixes building Nasm objects with Meson's native language support, when
depending against a library that exports that flag, like Glib.
diff --git a/mesonbuild/compilers/asm.py b/mesonbuild/compilers/asm.py
index bfe436b..e25f18d 100644
--- a/mesonbuild/compilers/asm.py
+++ b/mesonbuild/compilers/asm.py
@@ -75,7 +75,7 @@
     def unix_args_to_native(self, args: T.List[str]) -> T.List[str]:
         outargs: T.List[str] = []
         for arg in args:
-            if arg == '-pthread':
+            if arg in {'-mms-bitfields', '-pthread'}:
                 continue
             outargs.append(arg)
         return outargs