The motivation behind this is to alleviate the problem
described in NixOS#41340.
I'm not sure if this completely fixes the problem, but it
eliminates one more area where we can exceed command line
length limits.

This is essentially the same change as in NixOS#112449,
except for `ld-wrapper.sh` instead of `cc-wrapper.sh`.

However, that change alone was not enough; on macOS the
`ld` provided by `darwin.cctools` fails if you use process
substitution to generate the response file, so I put up a
PR to fix that:

tpoechtrager/cctools-port#131

… and I included a patch referencing that fix so that the
new `ld-wrapper` still works on macOS.

Without this fix `ld` fails when response files are enabled and
the command line length exceeds 64KB.  For more details, see:

tpoechtrager/cctools-port#132

The hash remains the same (I checked)