[llvm-jitlink] Cherry-pick jitlink-check fix for big endian systems

[weliveindetail]

We need the fix from #79970 on release/18.x as well.

[weliveindetail]

/cherry-pick 8a5bdd8

[llvmbot]

@llvm/issue-subscribers-jitlink

Author: Stefan Gränitz (weliveindetail)

We need the fix from https://github.com//pull/79970 on `release/18.x` as well.

[llvmbot]

/pull-request #80025

[weliveindetail]

This fix landed. Thanks everyone!