Use capi instead of ccall when importing stat/lstat on macOS

[harendra-kumar]

See PR #3191

Test failure:

streamly-tests     >   Streamly/Test/FileSystem/DirIO.hs:57:13: 
streamly-tests     >   1) FileSystem.DirIO.Symlink followSymlinks True
streamly-tests     >        expected: ["benchmark-tmp/dir-structure-small-sym", "benchmark-tmp/dir-structure-small-sym/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_1/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_1/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_1/dir_3", "benchmark-tmp/dir-structure-small-sym/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_2/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_2/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_2/dir_3", "benchmark-tmp/dir-structure-small-sym/dir_3", "benchmark-tmp/dir-structure-small-sym/dir_3/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_3/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_3/dir_3", "benchmark-tmp/dir-structure-small-sym/sym-link-1", "benchmark-tmp/dir-structure-small-sym/sym-link-1/dir_1", "benchmark-tmp/dir-structure-small-sym/sym-link-1/dir_2", "benchmark-tmp/dir-structure-small-sym/sym-link-1/dir_3", "benchmark-tmp/dir-structure-small-sym/sym-link-2"]
streamly-tests     >         but got: ["benchmark-tmp/dir-structure-small-sym", "benchmark-tmp/dir-structure-small-sym/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_1/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_1/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_1/dir_3", "benchmark-tmp/dir-structure-small-sym/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_2/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_2/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_2/dir_3", "benchmark-tmp/dir-structure-small-sym/dir_3", "benchmark-tmp/dir-structure-small-sym/dir_3/dir_1", "benchmark-tmp/dir-structure-small-sym/dir_3/dir_2", "benchmark-tmp/dir-structure-small-sym/dir_3/dir_3", "benchmark-tmp/dir-structure-small-sym/sym-link-1", "benchmark-tmp/dir-structure-small-sym/sym-link-2"]
streamly-tests     > 
streamly-tests     >   To rerun use: --match "/FileSystem.DirIO/Symlink/followSymlinks True/" --seed 2139695280
streamly-tests     > 
streamly-tests     > Randomized with seed 2139695280
streamly-tests     > 
streamly-tests     > Finished in 2.6469 seconds
streamly-tests     > 22 examples, 1 failure