Debugger: Implement expression variable value resolution.

General:
- Resolving variable values requires both a stack frame and a CPU state.
  Adjust all interfaces and callers accordingly.

ExpressionEvaluationJob:
- Pass additional parameters needed for variable value resolution.
- If variable resolution is desired, ExpressionEvaluationJob now
  creates a temporary ValueNodeManager for that purpose.
- If the expression parser returns a value node pointer that needs
  to be resolved, schedule a corresponding job and wait.

CLanguageExpressionEvaluator:
- Clean up some leftovers that were preventing variable names from being
  handled properly in some cases.
- Implement handling of identifier names. These are now looked up against
  the value node graph of the active node manager, and if found, corresponding
  values are retrieved. If the value has not yet been resolved, an exception
  is thrown to ask that to be done.

This gets value resolution working for basic local variables and function
parameters, and consequently, #9712. Structure/class members and/or pointer
indirection aren't yet handled.
writembr: Fix too short MBR due to wrong compile flags.

The compile flags were set so that only the boot code itself would be
produced, excluding the (dummy) partition table and signature. The code
in writembr still assumed that the MBR would be 512 bytes however and
therefore access the data array out of bounds.

Fix flags to produce the full 512 byte MBR sector and add a
STATIC_ASSERT so that the size assumption is checked on compilation.

Also fix a typo in mbr.nasm, mostly to trigger re-generation of the
MBR data that one would otherwise need to remove manually...

The two out of bounds array accesses were pointed out by CID 1249923 and
CID 1249924, the insufficiently large target buffer of the memcpy by
CID 1249901.
Re-enable raw audio ffmpeg output.
Avoid space after -include.

This seems to make cpp unhappy. Note that other fixes seems to be needed
to get the build running with gcc2 (missing includes and the like.)
Fix build of intel partitioning add-on by building its own MBR.

It previously shared the same generated MBR header with bin/writembr,
but they have incompatible needs. The intel partitioning add-on only
wants the MBR code, while writembr wants the whole sector.

Build the desired version of the MBR separately for each target instead
of sharing a single header.