A couple of Examples/concurrency

[deukhyun-cha]

Examples for 1) OpenMP streams to generalize the "stream" concept for all modes 2) Internal thread safe block for occa properties.

[deukhyun-cha]

• Created as a draft for any discussion before (or to decide) a merge.
• The original examples/concurrency branch seems behind for some commits from the development and needs to catch up.

[codecov[bot]]

Codecov Report

Attention: 103 lines in your changes are missing coverage. Please review.

Comparison is base (ec6e59d) 75.26% compared to head (519d104) 74.96%. Report is 1 commits behind head on examples/concurrency.

Additional details and impacted files

@@                   Coverage Diff                    @@
##           examples/concurrency     #736      +/-   ##
========================================================
- Coverage                 75.26%   74.96%   -0.30%     
========================================================
  Files                       297      298       +1     
  Lines                     19324    19486     +162     
========================================================
+ Hits                      14544    14608      +64     
- Misses                     4780     4878      +98     

Files	Coverage Δ
include/occa/core/memoryPool.tpp	100.00% <ø> (ø)
include/occa/functional/typelessArray.hpp	73.49% <100.00%> (ø)
src/c/base.cpp	85.71% <100.00%> (ø)
src/c/memoryPool.cpp	87.87% <100.00%> (ø)
src/core/base.cpp	72.82% <100.00%> (+2.17%)	:arrow_up:
src/core/kernel.cpp	85.93% <ø> (ø)
src/core/memory.cpp	84.71% <100.00%> (+1.38%)	:arrow_up:
src/occa/internal/core/device.hpp	100.00% <ø> (ø)
src/occa/internal/core/memory.cpp	100.00% <ø> (ø)
src/occa/internal/core/memoryPool.cpp	68.58% <ø> (ø)
... and 18 more

... and 3 files with indirect coverage changes