building and debugging on Mac without rpath

[Kirill Lykov]

Hi,

I experience, probably, a well known problem with mac that
DYLD_LIBRARY_PATH is flashed.
Maybe there is a flag in the arrow which helps overcoming this problem
already?

It appears when I try to debug my code:
```bash
lldb python
run
c
>> import pyarrow as pa
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File
"/Users/klykov1/Documents/workspace/arrow_copy/python/pyarrow/__init__.py",
line 63, in <module>
    import pyarrow.lib as _lib
ImportError:
dlopen(/Users/klykov1/Documents/workspace/arrow_copy/python/pyarrow/
lib.cpython-38-darwin.so, 2): Library not loaded: @rpath/libarrow.200.dylib
  Referenced from:
/Users/klykov1/Documents/workspace/arrow_copy/python/pyarrow/
lib.cpython-38-darwin.so
  Reason: image not found
```

I tried the following but seems it is not enough:
```
set(CMAKE_CXX_FLAGS "-Wl,-rpath,/arrowdir/dist/lib")
```

-- 
Best regards,
Kirill Lykov