[lldb][NFCI] Deprecate SBValue::GetOpaqueType

[bulbazord]

Summary

This method, as far as I can ascertain, is non-trivial to actually use
to work with (if not impossible). It doesn't make sense to use from
Python and you do not have access to the accompanying TypeSystem, so it
doesn't really do anything useful.

A possible follow-up is to gut the implementation and have it return nullptr.

[JDevlieghere]

lldb/include/lldb/API/SBValue.h

286

Similar comment as in D153900: The "Do not use." part is redundant and implied by the deprecation.

[mib]

lldb/include/lldb/API/SBValue.h

286

Should we add a macro like for LLDB_INVALID_* to act as the FIX argument ? It feels wrong to pass an empty string.

[bulbazord]

lldb/include/lldb/API/SBValue.h

286

Yeah, I think it would be useful to distinguish between deprecations for "we have a better way to do this now" and "we probably shouldn't be exposing this method". I'll submit a separate change for that.

[bulbazord]

Address feedback

[JDevlieghere]

LGTM

lldb/include/lldb/API/SBValue.h

public:
   bool MightHaveChildren();
 
   bool IsRuntimeSupportValue();
 
   uint32_t GetNumChildren();
 
   uint32_t GetNumChildren(uint32_t max);
 
+  LLDB_DEPRECATED("SBValue::GetOpaqueType() is deprecated.")
   void *GetOpaqueType();
 
   lldb::SBTarget GetTarget();
 
   lldb::SBProcess GetProcess();
 
   lldb::SBThread GetThread();