[lld][WebAssembly] Handle TLS symbols in older object file

In older versions of llvm (e.g. llvm 13), symbols were not individually
flagged as TLS.  In this case, the indent was to implicitly mark any
symbols defined in TLS segments as TLS.  However, we were not performing
this implicit conversion if the segment was explicitly marked as TLS

As it happens, llvm 13 was branched between the addition of the segment
flag and the addition of the symbol flag. See:

- segment flag added: https://reviews.llvm.org/D102202
- symbol flag added: https://reviews.llvm.org/D109426

Testing this is tricky because the assembler will imply the TLS status
of the symbol based on the segment its declared in, so we are forced to
use a yaml file here.

Fixes: https://github.com/emscripten-core/emscripten/issues/15891

Differential Revision: https://reviews.llvm.org/D118414