[lldb/Reproducers] Always collect the whole dSYM in the reproducer

The FileCollector in LLDB collects every files that's used during a
debug session when capture is enabled. This ensures that the reproducer
only contains the files necessary to reproduce. This approach is not a
good fit for the dSYM bundle, which is a directory on disk, but should
be treated as a single unit.

On macOS LLDB have automatically find the matching dSYM for a binary by
its UUID. Having a incomplete dSYM in a reproducer can break debugging
even when reproducers are disabled.

This patch adds a was to specify a directory of interest to the
reproducers. It is called from SymbolVendorMacOSX with the path of the
dSYMs used by LLDB.

Differential revision: https://reviews.llvm.org/D76672