TLS-relative relocations always need to be relative the TLS section
since they get added to `__tls_base` at runtime.
Without this change the tls base address was effectively being added to
the final value twice in this case.
This only effects code the is built with `-pthread` but linked without
shared memory (i.e. without threads).
Fixes: https://github.com/emscripten-core/emscripten/issues/22880
1c1fbf51b5