Upgrade to APR(*) 1.6.x and work around Xcode12 over-agressive clang warning/errors

(cherry picked from commit b1dc36c01638ed0d08b23f216ee4fa310c82a82b)
10 files changed
tree: 7ae29d250d509d45fb9065cf260f653bd0d8adb8
  1. ext_libraries/
  2. ext_sources/
  3. extras/
  4. main/
  5. test/
  6. .gitignore