[Triton-MLIR]Add ptx vprintf support (#825)

Not know how to write unit test for this feature.

Co-authored-by: Yan Chunwei <yanchunwei@outlook.com>

python/tests/test_printf.py

@@ -0,0 +1,21 @@
+import os
+import subprocess
+
+dir_path = os.path.dirname(os.path.realpath(__file__))
+printf_path = os.path.join(dir_path, "printf_helper.py")
+
+
+def test_printf():
+    proc = subprocess.Popen(["python", printf_path], stdout=subprocess.PIPE, shell=False)
+    (outs, err) = proc.communicate()
+    outs = outs.split()
+    new_lines = set()
+    for line in outs:
+        try:
+            value = int(float(line))
+            new_lines.add(value)
+        except Exception as e:
+            print(e)
+    for i in range(128):
+        assert i in new_lines
+    assert len(new_lines) == 128