When using the linker flags `--icf=safe_thunks` and `--keep-icf-stabs`
together, an issue arises with the STABS debugging entries in the linked
output. The problem affects STABS entries for functions that are folded
via ICF using thunks.
For instance, if `func1` is merged into `func2` through a thunk, the
STABS entry for `func1` incorrectly points to the object file of
`func2`. This is incorrect behavior—each function’s STABS entry should
consistently point to its own original object file (e.g., the STABS
entry for `func1` should reference `func1`’s object file). This issue
causes `dsymutil` to not be able to retrieve the debug information for
the problematic function.
This patch corrects this behavior - making it so that STABS entries
always point to the correct object file.
57e5b82e8c