Add more array helper functions, add U64 to I64 saturate cast

dqn_helpers.cpp

@@ -585,16 +585,19 @@ DQN_API uint64_t Dqn_Safe_SaturateCastUSizeToU64(Dqn_usize val)
     return result;
 }
 
-// NOTE: Dqn_Safe_SaturateCastU64To*
-// -----------------------------------------------------------------------------
-// INT*_MAX literals will be promoted to the type of val as val is
-// the highest possible rank (unsigned > signed).
+// NOTE: Dqn_Safe_SaturateCastU64To* ///////////////////////////////////////////////////////////////
 DQN_API int Dqn_Safe_SaturateCastU64ToInt(uint64_t val)
 {
     int result = DQN_CHECK(val <= INT_MAX) ? DQN_CAST(int)val : INT_MAX;
     return result;
 }
 
+DQN_API int64_t Dqn_Safe_SaturateCastU64ToI64(uint64_t val)
+{
+    int64_t result = DQN_CHECK(val <= INT64_MAX) ? DQN_CAST(int64_t)val : INT64_MAX;
+    return result;
+}
+
 // Both operands are unsigned and the lowest rank operand will be promoted to
 // match the highest rank operand.
 DQN_API unsigned int Dqn_Safe_SaturateCastU64ToUInt(uint64_t val)