[m-rev.] for review: update to Boehm GC v8.2.4

[Julien Fischer]

Hi Peter,

On Mon, 10 Jul 2023, Peter Wang wrote:

> I've pushed the tag 'release-8_2-mercury-20230706-rc' to our
> bdwgc repository. Can you test it on MacOS and Windows?
>
> So far I've tested it on
>    Linux (x86-64, i686, aarch64)
>    FreeBSD (x86-64)
>    OpenBSD (x86-64)
>    MinGW-w64 x86-64 (cross-compiled only)

The following are ok:

     macOS (x86_64)
     MinGW-w64 x86_64 UCRT64

There is an issue with the 64-bit version of MSVC:

../scripts/ml --grade hlc.gc    --no-mercury-stdlib-dir
--trace-init-file ../browser/mer_browser.init --trace-init-file
../mdbcomp/mer_mdbcomp.init --ssdb-init-file ../ssdb/mer_ssdb.init
--    -Fechoose_grade.exe choose_grade_init.obj \
         choose_grade.obj grade_lib.obj grade_lib.grade_setup.obj
grade_lib.grade_solver.obj grade_lib.grade_spec.obj
grade_lib.grade_state.obj grade_lib.grade_string.obj
grade_lib.grade_structure.obj grade_lib.grade_vars.obj
var_value_names.obj \
         ../trace/libmer_trace.lib ../trace/libmer_eventspec.lib
../ssdb/libmer_ssdb.lib ../browser/libmer_browser.lib
../mdbcomp/libmer_mdbcomp.lib ../library/libmer_std.lib
../runtime/libmer_rt.lib ../boehm_gc/libgc.lib
libgc.lib(misc.obj) : error LNK2019: unresolved external symbol
__imp_MessageBoxA referenced in function GC_win32_MessageBoxA

Julien.