add support for metadata.

add related test.

test/metadata.py

@@ -0,0 +1,28 @@
+import unittest
+
+from llvm.core import *
+
+class TestMetaData(unittest.TestCase):
+    def test_metadata_get(self):
+        module = Module.new('test_metadata')
+        md = MetaData.get(module, [Constant.int(Type.int(), 1234)])
+
+    def test_meta_load_nt(self):
+        module = Module.new('test_meta_load_nt')
+        func = module.add_function(Type.function(Type.void(), []),
+                                   name='test_load_nt')
+        bldr = Builder.new(func.append_basic_block('entry'))
+        addr = Constant.int(Type.int(), 0xdeadbeef)
+        loadinst = bldr.load(bldr.inttoptr(addr, Type.pointer(Type.int(8))))
+
+        md = MetaData.get(module, [Constant.int(Type.int(), 1)])
+        loadinst.set_metadata('nontemporal', md)
+
+        bldr.ret_void()
+        module.verify()
+
+        self.assertIn('!nontemporal', str(loadinst))
+
+if __name__ == '__main__':
+    unittest.main()
+