Implement five _mm_cmpestr

[Cuda-Chen]

Implement _mm_cmpestra, _mm_cmpestrc, _mm_cmpestro, _mm_cmpestrs, and _mm_cmpestrz.

[jserv]

Are you ready to close #308 ? If so, append Close #308 at the end of git commit message.

[Cuda-Chen]

Are you ready to close #308 ? If so, append Close #308 at the end of git commit message.

The _mm_cmpistr series has not be implemented yet.
However, should we create another issue to track the progress of implementing _mm_cmpistr series?

[jserv]

should we create another issue to track the progress of implementing _mm_cmpistr series?

No, let's track on #308

[jserv]

Would you modify the function body of _mm_cmpestri and _mm_cmpestrm as well?

[Cuda-Chen]

The SSE2NEON_CMPESTRX_GET_UPPER_BOUND macro is used for getting upper-bound of byte/word. What's more, _mm_cmpestrs and _mm_cmpestrz need the upper-bound information to decide whether the input string hits upper-bound or not.