Convert Bash usage to a Python script.

test cases/common/41 test args/meson.build

@@ -38,10 +38,10 @@ test('custom target arg', tester, args : testfilect, env : env_array)
 env = environment()
 env.append('PATH', 'something')
 
-bash = find_program('bash')
+pathtester = find_program('pathtester.py')
 
 custompathtgt = custom_target('testpathappend',
                               output : 'nothing.txt',
                               build_always : true,
-                              command : [bash, '-c', 'env'],
+                              command : [pathtester],
                               env : env)

test cases/common/41 test args/pathtester.py

@@ -0,0 +1,11 @@
+#!/usr/bin/env python3
+
+import sys, subprocess
+
+if sys.platorm() == 'win32':
+    cmd = ['xcopy', '/?']
+else:
+    cmd = ['env']
+
+rc = subprocess.run(cmd, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+sys.exit(rc.returncode)