[lldb][debugserver] Get the size of the shared cache in mapped VM (#187419)
Fetch the size of the shared cache address range in VM in the inferior
process and return it, if possible. This allows for a simple call to
DynamicLoader::GetSharedCacheInformation to get the virtual address
extent of the shared cache in the inferior. It's a minor addition to the
method that fetches the shared cache filepath from the inferior, plus
piping it up through lldb's layers.
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Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>