Merge branch 'size_t' into 'master'

Improve portability of size_t and ptrdiff_t on recent compilers

Closes #157

See merge request !478
109 jobs for master in 52 minutes and 54 seconds (queued for 12 seconds)
Name Stage Failure
failed
clang_10.0_hybrid_dbg_sp Pretest
Running after_script
Running after script...
$ python3 cmake/ctest2junit.py build > report.xml
Uploading artifacts for failed job
Uploading artifacts...
report.xml: found 1 matching files and directories

WARNING: python/report.xml: no matching files
Uploading artifacts as "junit" to coordinator... ok
id=628646 responseStatus=201 Created token=-SadHmNQ
Cleaning up file based variables
ERROR: Job failed: exit code 1
failed
gcc_11_hybrid Pretest
Running after_script
Running after script...
$ python3 cmake/ctest2junit.py build > report.xml
Uploading artifacts for failed job
Uploading artifacts...
report.xml: found 1 matching files and directories

python/report.xml: found 1 matching files and directories

Uploading artifacts as "junit" to coordinator... ok
id=628645 responseStatus=201 Created token=56X7L7ai
Cleaning up file based variables
ERROR: Job failed: exit code 1