[llvm-branch-commits] [lld] Update cgdata-* tests to not use subshells (PR #156533)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/156533

Subshells are not supported in the lit internal shell. We can remove
them by constructing sed commands directly inside of a separate file.

Towards #102700.