E.g. on CHERI pointers are 128 bits [1]. This causes the unit3214 test
to fail, which was written with more traditional platforms in mind. Here
is the output of log/stderr3214:
```
URL: -
BAD: struct Curl_easy is 7984 bytes, allowed to be 5370: 2614 bytes too big
BAD: struct connectdata is 1408 bytes, allowed to be 1300: 108 bytes too big
BAD: struct Curl_multi is 1248 bytes, allowed to be 850: 398 bytes too big
BAD: struct curl_httppost is 224 bytes, allowed to be 112: 112 bytes too big
BAD: struct curl_slist is 32 bytes, allowed to be 16: 16 bytes too big
BAD: struct curl_khkey is 32 bytes, allowed to be 24: 8 bytes too big
BAD: struct curl_hstsentry is 48 bytes, allowed to be 40: 8 bytes too big
BAD: struct curl_mime is 144 bytes, allowed to be 96: 48 bytes too big
BAD: struct curl_mimepart is 592 bytes, allowed to be 440: 152 bytes too big
BAD: struct curl_certinfo is 32 bytes, allowed to be 16: 16 bytes too big
BAD: struct curl_tlssessioninfo is 32 bytes, allowed to be 16: 16 bytes too big
BAD: struct curl_blob is 32 bytes, allowed to be 24: 8 bytes too big
BAD: struct CURLMsg is 48 bytes, allowed to be 24: 24 bytes too big
BAD: struct curl_header is 80 bytes, allowed to be 48: 32 bytes too big
Test ended with result 14
```
Multiply the allowed size on systems with larger than 64-bit pointers.
[1] https://www.cl.cam.ac.uk/research/security/ctsrd/pdfs/20171017a-cheri-poster.pdfCloses#22299