[lld] [lld] Mark target section as code section when merging code sections into a data section. (PR #72030)

[Jacek Caban via llvm-commits]

cjacek wrote:

Thanks for review! I realized that the test for uninitialized data was not testing what I intended, it should be fixed in the fixup.

https://github.com/llvm/llvm-project/pull/72030