Minimal reproducer and source pointer for a musl dynamic-linker relocation issue.

The reproducer builds a PIE with an x86-64 R_X86_64_64 relocation against an
SHN_ABS symbol exported by a DSO. The expected relocated value is S + A. On the
tested musl loaders, the observed value behaves as B + S + A, where B is the
DSO load base.

The archive includes the email draft, exact source-line notes, source-only repro
inputs, the repro script, and saved outputs from system musl 1.2.4 and official
musl 1.2.6.
