Undefined reference when linking shared libraries not raised

[mattparks]

I have an example where two shared libraries (A and B) don't link with -z defs; and where C does build with -z defs and links both libraries.
This example includes an mistake where B attempts to use a local from A (helper_a()). When linking with ld an undefined reference error is raised. This does not occur with Mold with the same linker flags, transforming this mistake into a runtime error.

If helper_a() were not defined in A at all, there is still no error raised with Mold, I don't think symbol visibility matters in this example.

I tested with mold 2.32.1, attached is the described example project:
mold_vs_ld_undefined_symbols.zip

[rui314]

Please try again with the above change.