Fix macro generation

1) We don't need ULL modifier because of https://en.cppreference.com/w/c/language/integer_constant (look at `The type of the integer constant` section)
2) We need to add U modifier to all values to fix some issues with `set_field` and `get_field` macros (for example, when `mask` = 1 << 31, it leads to UB becuase of signed overflow)

registers.py

@@ -386,26 +386,17 @@ def prototype(self):
     def body(self):
         return self.expression
 
-def sympy_to_c(expression, sym_to_c = lambda s: "(" + str(s) + ")"):
+def sympy_to_c(expression, sym_to_c = lambda s: f"({s})", unsigned=True):
     """Implement our own string function, so we can replace 2** with 1<<."""
     stc = lambda x : sympy_to_c(x, sym_to_c)
     if isinstance(expression, str):
         return expression
     if isinstance(expression, sympy.Number):
-        if (expression >= 2**32):
-            return "0x%xULL" % expression
-        elif (expression >= 2**31):
-            return "0x%xU" % expression
-        elif (expression >= 10):
-            return "0x%x" % expression
-        elif (expression > -10):
-            return "%d" % expression
-        elif (expression > -2**31):
-            return "-0x%x" % -expression
-        elif (expression > -2**32):
-            return "-0x%xU" % -expression
+        sufffix = "U" if unsigned else ""
+        if (expression < 10 and expression > -10):
+            return "%d%s" % (expression, sufffix)
         else:
-            return "-0x%xULL" % -expression
+            return "%#0x%s" % (expression, sufffix)
     elif isinstance(expression, sympy.Symbol):
         return sym_to_c(expression)
     elif isinstance(expression, sympy.Add):