Fix macOS mod_tile.c builds

[hummeltech]

• Use a local allocator for data buffers

[codecov-commenter]

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Codecov Report

❌ Patch coverage is 70.90909% with 16 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.89%. Comparing base (c4e3e62) to head (efa5213).
⚠️ Report is 25 commits behind head on master.

Files with missing lines	Patch %	Lines
src/mod_tile.c	70.90%	16 Missing ⚠️
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Additional details and impacted files

@@            Coverage Diff             @@
##           master     #492      +/-   ##
==========================================
- Coverage   81.54%   80.89%   -0.65%     
==========================================
  Files          24       24              
  Lines        5645     5234     -411     
==========================================
- Hits         4603     4234     -369     
+ Misses       1042     1000      -42     

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