Fixes "Use of uninitialized value $Flaky" message in testbot reports.

Fixes "Use of uninitialized value $Flaky" message in testbot reports.

Fixes "Use of uninitialized value $Flaky" message in testbot reports.

This change is adding DWARF (CFI) unwind information to the
hand-written assembly of the `__wine_syscall_dispatcher` function.
This enables unwinding through the dispatcher from the Linux stack
into (and through) the Windows stack.

The general idea is that the `syscall_frame` struct contains the
content of the callee-save registers before the function call
(in particular the stack pointer and the return address). At any
point of the execution, we have a pointer into the `syscall_frame`
in $rcx, $rbp or $rsp.

For the CFI codes the general idea is that we are defining the
computations of the callee-save registers based on the
`syscall_frame` using DWARF’s `breg` instruction, rather than
relative to CFA.

This change adds a bunch of convenience macros, to (hopefully)
improve readability of the CFI instructions.

Note: Those change was used with great success for unwinding through
the dispatcher using a modified LLDB shown in the
“how-wine-works-101” (https://werat.dev/blog/how-wine-works-101/)
blog post as well as for in the Orbit profiler
(https://github.com/google/orbit), that has mixed-callstack
unwinding support.

Test: Inspect callstacks reported by the Orbit profiler while
running some Windows targets using the modified wine, as well as
verify debugging reports correct callstacks when stepping with our
modified LLDB through the dispatcher itself (so that we are able
to unwind through the dispatcher at any instruction).

Needed to compile Tera Term.

On FreeBSD 12 and 14 ENODATA is not regularly defined. Cater to that
in fd_get_file_info() and get_file_info().

In some 32bit modules, MingW/GCC generates in Dwarf debug information,
a cfa address to be computed as:
   deref(register XX + offset)
which is too complicated to be expressed through regular DbgHelp APIs.

So silence the FIXME, and report a 'too complex' error (instead of
'internal').

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52790Signed-off-by: Eric Pouech <eric.pouech@gmail.com>

This improves correctness of functions like SymFromAddr()
when searching local variables.
Signed-off-by: Eric Pouech <eric.pouech@gmail.com>

Signed-off-by: Eric Pouech <eric.pouech@gmail.com>

- split in two sub helpers (one to get size, the other to fill content in)
  (this avoids reallocating buffer)
- return error in case no range is present (but range dwarf attribute is)
Signed-off-by: Eric Pouech <eric.pouech@gmail.com>

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45273

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45273

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45273

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45273

Needed to compile PuTTY.