TESTS: For callback with None return type

Author: ubaidsk

integration_tests/CMakeLists.txt

@@ -722,6 +722,7 @@ RUN(NAME global_syms_06    LABELS cpython llvm c)
 
 RUN(NAME callback_01       LABELS cpython llvm c)
 RUN(NAME callback_02       LABELS cpython llvm c)
+RUN(NAME callback_03       LABELS cpython llvm c)
 
 # Intrinsic Functions
 RUN(NAME intrinsics_01     LABELS cpython llvm NOFAST) # any

integration_tests/callback_03.py

@@ -0,0 +1,13 @@
+from lpython import i32, Callable
+
+def foo(x : i32) -> None:
+    print(x)
+    assert x == 3
+
+def bar(func : Callable[[i32], None], arg : i32) -> i32:
+    func(arg)
+
+def main0():
+    bar(foo, 3)
+
+main0()