Fix range overflow when using signed integers

tests/functional/codegen/features/iteration/test_for_range.py

@@ -414,3 +414,19 @@ def foo(a: {typ}) -> {typ}:
     assert c.foo(100) == 6
     assert c.foo(1) == 666
     assert c.foo(0) == 31337
+
+
+def test_for_range_signed_int_overflow(get_contract, tx_failed):
+    code = """
+@external
+def foo() -> DynArray[int256, 10]:
+    res: DynArray[int256, 10] = empty(DynArray[int256, 10])
+    x:int256 = max_value(int256)
+    y:int256 = min_value(int256)+2
+    for i:int256 in range(x,y , bound=10):
+        res.append(i)
+    return res
+    """
+    c = get_contract(code)
+    with tx_failed():
+        c.foo()

vyper/codegen/stmt.py

@@ -255,7 +255,7 @@ def _parse_For_range(self):
             with end.cache_when_complex("end") as (b1, end):
                 # note: the check for rounds<=rounds_bound happens in asm
                 # generation for `repeat`.
-                clamped_start = clamp("le", start, end)
+                clamped_start = clamp("sle" if target_type.is_signed else "le", start, end)
                 rounds = b1.resolve(IRnode.from_list(["sub", end, clamped_start]))
             rounds_bound = kwargs.pop("bound").int_value()
         else: