Adjust hb_is_signed<>

Fixes https://github.com/harfbuzz/harfbuzz/issues/1535

src/hb-dsalgs.hh

@@ -299,24 +299,15 @@ hb_ceil_to_4 (unsigned int v)
 }
 
 template <typename T> struct hb_is_signed;
-template <> struct hb_is_signed<signed char> { enum { value = true }; };
-template <> struct hb_is_signed<signed short> { enum { value = true }; };
-template <> struct hb_is_signed<signed int> { enum { value = true }; };
-template <> struct hb_is_signed<signed long> { enum { value = true }; };
-template <> struct hb_is_signed<unsigned char> { enum { value = false }; };
-template <> struct hb_is_signed<unsigned short> { enum { value = false }; };
-template <> struct hb_is_signed<unsigned int> { enum { value = false }; };
-template <> struct hb_is_signed<unsigned long> { enum { value = false }; };
-/* We need to define hb_is_signed for the typedefs we use on pre-Visual
- * Studio 2010 for the int8_t type, since __int8/__int64 is not considered
- * the same as char/long.  The previous lines will suffice for the other
- * types, though.  Note that somehow, unsigned __int8 is considered same
- * as unsigned char.
- * https://github.com/harfbuzz/harfbuzz/pull/1499
- */
-#if defined(_MSC_VER) && (_MSC_VER < 1600)
-template <> struct hb_is_signed<__int8> { enum { value = true }; };
-#endif
+/* https://github.com/harfbuzz/harfbuzz/issues/1535 */
+template <> struct hb_is_signed<int8_t> { enum { value = true }; };
+template <> struct hb_is_signed<int16_t> { enum { value = true }; };
+template <> struct hb_is_signed<int32_t> { enum { value = true }; };
+template <> struct hb_is_signed<int64_t> { enum { value = true }; };
+template <> struct hb_is_signed<uint8_t> { enum { value = false }; };
+template <> struct hb_is_signed<uint16_t> { enum { value = false }; };
+template <> struct hb_is_signed<uint32_t> { enum { value = false }; };
+template <> struct hb_is_signed<uint64_t> { enum { value = false }; };
 
 template <typename T> static inline bool
 hb_in_range (T u, T lo, T hi)