bindist configure fails when LDFLAGS contains pack-relative-locs

Summary

Running ./configure from the bindist with an LDFLAGS containing -Wl,-z,pack-relative-relocs fails when trying to determine machine word size. I run into this issue when installing a GHC through stack within a PKGBUILD on Arch Linux -- the default LDFLAGS setting there contains -Wl,-z,pack-relative-relocs since last month. Raised the issue both in stack and Arch Linux repos before being prodded by @maerwald that this might need to be addressed via GHC as well

GHC isn't the only Haskell program affected, I similarly have trouble building unix and network. I haven't investigated these in-depth, but suspect the issue is a similar use of autoconfig for the ffi bits which fails. Raised issue in cabal to see if they can't similarly select $LD based on $LDFLAGS.

Steps to reproduce

With eg the 9.6.4 fedora bindist:

export LDFLAGS='-Wl,-z,pack-relative-relocs'
./configure

Expected behavior

Configuration should succeed, just like it does without LDFLAGS set.

Environment

• GHC version used: 9.6.4

Optional:

• Operating System: Arch Linux
• System Architecture: x86_64