If a server does not support allocating memory in an inferior process or
when debugging a core file, evaluating an expression in the context of a
value object results in an error:

```
error: <lldb wrapper prefix>:43:1: use of undeclared identifier '$__lldb_class'
   43 | $__lldb_class::$__lldb_expr(void *$__lldb_arg)
      | ^
```

Such expressions require a live address to be stored in the value
object. However, `EntityResultVariable::Dematerialize()` only sets
`ret->m_live_sp` if JIT is available, even if the address points to the
process memory and no custom allocations were made. Similarly,
`EntityPersistentVariable::Dematerialize()` tries to deallocate memory
based on the same check, resulting in an error if the memory was not
previously allocated in `EntityPersistentVariable::Materialize()`.

As an unintended bonus, the patch also fixes a FIXME case in
`TestCxxChar8_t.py`.

This will make changes in #145599 a bit nicer.

Reapply "[NFC][DebugInfo][DWARF] Create new low-level dwarf library (#…
(#145959)
    
This reapplies cbf781f0bdf2f680abbe784faedeefd6f84c246e, with fixes for
the shared-library build and the unconventional sanitizer-runtime build.

Original Description:

This is the culmination of a series of changes described in [1].
    
Although somewhat large by line count, it is almost entirely mechanical,
creating a new library in DebugInfo/DWARF/LowLevel. This new library has
very minimal dependencies, allowing it to be used from more places than
the normal DebugInfo/DWARF library--in particular from MC.
    
1.
https://discourse.llvm.org/t/rfc-debuginfo-dwarf-refactor-into-to-lower-and-higher-level-libraries/86665/2

…145081)"

This reverts commit cbf781f0bdf2f680abbe784faedeefd6f84c246e.

Breaks a couple of buildbots.

This is the culmination of a series of changes described in [1].
    
Although somewhat large by line count, it is almost entirely mechanical,
creating a new library in DebugInfo/DWARF/LowLevel. This new library has
very minimal dependencies, allowing it to be used from more places than
the normal DebugInfo/DWARF library--in particular from MC.
    
I am happy to put it in another location, or to structure it differently
if that makes sense. Some have suggested in BinaryFormat, but it is not
a great fit there. But if that makes more sense to the reviewers, I can
do that.
 
Another possibility would be to use pass-through headers to allow
clients who don't care to depend only on DebugInfo/DWARF. This would be
a much less invasive change, and perhaps easier for clients. But also a
system that hides details.

Either way, I'm open.

1.
https://discourse.llvm.org/t/rfc-debuginfo-dwarf-refactor-into-to-lower-and-higher-level-libraries/86665/2

Replace (questionable) header globs with an explicit argument supported
by llvm_add_library.

(Revised version of a previous, unreviewed, PR.)

Move all expression verification into its only client: DWARFVerifier.
Move all printing code (which was a mix of static and member functions)
into a separate class.

This is one in a series of refactoring PRs to separate dwarf
functionality into lower-level pieces usable without object files and
sections at build time. The code is already written this way via various
"if (section == nullptr)" and similar conditionals. So the functionality
itself is needed and exists, but only as a runtime feature. The goal of
these refactors is to remove the build-time dependencies, which will
allow the existing functionality to be used from lower-level parts of
the compiler. Particularly from lib/MC/.... More information at:


https://discourse.llvm.org/t/rfc-debuginfo-dwarf-refactor-into-to-lower-and-higher-level-libraries/86665

This patch should be mostly obvious, but in one place, this patch
changes:

  const auto &it = std::find(...)

to:

  auto it = llvm::find(...)

We do not need to bind to a temporary with const ref.

If we're not touching them, we don't need to do anything special to pass
them along -- with one important caveat: due to how cmake arguments
work, the implicitly passed arguments need to be specified before
arguments that we handle.

This isn't particularly nice, but the alternative is enumerating all
arguments that can be used by llvm_add_library and the macros it calls
(it also relies on implicit passing of some arguments to
llvm_process_sources).