[lldb][Windows] Fix value API tests (#214237)
This removes the XFAILs for the value API tests.
- For `lldb/test/API/python_api/value/TestValueAPI.py`, we need to pass
`/debug:symtab` to the linker to get a symbol table. Symbols are
"hidden" by default. PDB works around this in the publics stream. For
DWARF, we need `/debug:symtab`. An alternative is to use `/debug:dwarf`
which also enables this.
- For
`lldb/test/API/python_api/value/change_values/TestChangeValueAPI.py`
there were two issues. First, the stdout wasn't available when we
stopped at a breakpoint. Adding a `fflush(stdout)` fixes this.
Secondly, the breakpoint was created where the inputs to `printf` were
already evaluated. I added another assignment where we set the
breakpoint.
The added `fflush` might also help with this being flakey on Linux
(#26026).
Closes #25146
