Add 32-bit u64_mul10_gt version

Author: mlazdans

firebird_utils.cpp

@@ -251,10 +251,18 @@ extern "C" int fbu_insert_field_info(void *master_ptr, ISC_STATUS* st, int is_ou
 #include <intrin.h>
 static int u64_mul10_gt(uint64_t r, uint64_t digit, uint64_t max, uint64_t *out)
 {
+#ifdef _WIN64
 	uint64_t hi, lo = _umul128(r, 10, &hi);
 	if (hi || lo > max - digit) return 1;
 	*out = lo + digit;
 	return 0;
+#else
+	// TODO: needs testing
+	/* x86: no _umul128; equivalent overflow check without 128-bit arithmetic */
+	if (r > (max - digit) / 10) return 1;
+	*out = r * 10 + digit;
+	return 0;
+#endif
 }
 #else
 static int u64_mul10_gt(uint64_t r, uint64_t digit, uint64_t max, uint64_t *out)