Allow JITFunction to return multiple results

rewrite-test/jit/multi-return.py

@@ -0,0 +1,27 @@
+import triton
+import triton.language as tl
+import triton._C.libtriton.triton as _triton
+
+
+@triton.jit
+def foo(a, b):
+  max, min = maxmin(a, b)
+  return max, min
+
+@triton.jit
+def maxmin(a, b):
+  max = tl.maximum(a, b)
+  min = tl.minimum(a, b)
+  return max, min
+
+
+mod, ctx = foo.compile_to_ttir(3, 4, grid=(1,))
+assert mod.verify()
+mod.dump()
+
+
+pm = _triton.ir.pass_manager(ctx)
+pm.add_inliner_pass()
+pm.run(mod)
+assert mod.verify()
+mod.dump()