Revert "meson: fix -Wno-foo argument testing"

This reverts commit bc315aa2881949d3961c03599e8c20e0273ec817

Turns out since meson 0.46 it knows about this quirk of compilers and
checks the right thing internally.

See https://github.com/mesonbuild/meson/pull/2284
diff --git a/meson.build b/meson.build
index e39353d..7826dbb 100644
--- a/meson.build
+++ b/meson.build
@@ -66,23 +66,16 @@
 
 global_args = []
 global_args_maybe = [
+	'-Wno-unused-parameter',
+	'-Wno-shift-negative-value', # required due to Pixman
+	'-Wno-missing-field-initializers',
 	'-fvisibility=hidden',
 ]
-global_wnoargs_maybe = [
-	'unused-parameter',
-	'shift-negative-value', # required due to Pixman
-	'missing-field-initializers',
-]
 foreach a : global_args_maybe
 	if cc.has_argument(a)
 		global_args += a
 	endif
 endforeach
-foreach a : global_wnoargs_maybe
-	if cc.has_argument('-W' + a)
-		global_args += '-Wno-' + a
-	endif
-endforeach
 add_global_arguments(global_args, language: 'c')
 
 if cc.has_header_symbol('sys/sysmacros.h', 'major')