python3: Add tests for sysconfig_path() and language_version()

test cases/python3/1 basic/meson.build

@@ -3,6 +3,16 @@ project('python sample', 'c')
 py3_mod = import('python3')
 py3 = py3_mod.find_python()
 
+py3_version = py3_mod.language_version()
+if py3_version.version_compare('< 3.2')
+  error('Invalid python version!?')
+endif
+
+py3_purelib = py3_mod.sysconfig_path('purelib')
+if not py3_purelib.endswith('site-packages')
+  error('Python3 purelib path seems invalid?')
+endif
+
 main = files('prog.py')
 
 test('toplevel', py3, args : main)