uint16_t was used to get scratch space offset. Largest value that can be
encoded for this type is 65536. Each scratch slot using HWord message is
32 bytes. So uint16_t usage is correct only up to 2048 HWord slots. When later sHWord slots are accessed, uint16_t goes OOB. This causes dependency check to become incorrect.

Fix is to use larger size (uint32_t) that can never go OOB.

(cherry picked from commit 10f146fe24343b0ca2a2ad23ea512c393a00bfda)