[lldb] Add IsFullyInitialized to DynamicLoader

On Darwin based systems, lldb will get notified by dyld before it itself
finished initializing, at which point it's not safe to call certain APIs
or SPIs. Add a method to the DynamicLoader to query that.

Differential revision: https://reviews.llvm.org/D99314

GitOrigin-RevId: bbb419151cc8994b3447f184fe841e87e159e5a3
3 files changed