git-compat-util.h: implement checked size_t to uint32_t conversion

In a similar fashion as other checked cast functions in this header
(such as `cast_size_t_to_ulong()` and `cast_size_t_to_int()`), implement
a checked cast function for going from a size_t to a uint32_t value.

This function will be utilized in a future commit which needs to make
such a conversion.

Signed-off-by: Taylor Blau <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: ttaylorr

git-compat-util.h

@@ -1013,6 +1013,15 @@ static inline unsigned long cast_size_t_to_ulong(size_t a)
 	return (unsigned long)a;
 }
 
+static inline uint32_t cast_size_t_to_uint32_t(size_t a)
+{
+	if (a != (uint32_t)a)
+		die("object too large to read on this platform: %"
+		    PRIuMAX" is cut off to %u",
+		    (uintmax_t)a, (uint32_t)a);
+	return (uint32_t)a;
+}
+
 static inline int cast_size_t_to_int(size_t a)
 {
 	if (a > INT_MAX)