Fix np.pad() casting

Author: arshajii

stdlib/numpy/format.codon

@@ -57,8 +57,8 @@ class FloatingFormat:
             self.__init__()
             return
 
-        min_val = None
-        max_val = None
+        min_val: Optional[a.dtype] = None
+        max_val: Optional[a.dtype] = None
         finite = 0
         abs_non_zero = 0
         exp_format = False

stdlib/numpy/routines.codon

@@ -2661,7 +2661,7 @@ def pad(array, pad_width, mode = 'constant', **kwargs):
         if dtype is int or isinstance(dtype, Int) or isinstance(dtype, UInt):
             return util.cast(util.rint(x), dtype)
         else:
-            return x
+            return util.cast(x, dtype)
 
     def pad_from_function(a: ndarray, pw, padding_func, kwargs, extra = None):
         shape = a.shape
@@ -2915,7 +2915,7 @@ def pad(array, pad_width, mode = 'constant', **kwargs):
         fill_linear(vector,
                     offset=(n - p2),
                     start=util.cast(end2, float),
-                    stop=util.cast(start1, float),
+                    stop=util.cast(start2, float),
                     num=p2,
                     rev=True)