external/python3: Silence UBSan errors with --with-pydebug

...that happen when building ExternalProject_python3 itself after
12142490cd43f8568ab29e0ddfa75b334d6d39d5 "Enable Python Py_DEBUG setting when
built with --enable-dbgutil on Linux":

For one, silence

> Modules/posixmodule.c:14395:9: runtime error: left shift of 34 by 26 places cannot be represented in type 'int'
>  #0 in all_ins at workdir/UnpackedTarball/python3/./Modules/posixmodule.c:14395:9

where at least my kernel-headers-5.9.9-200.fc33.x86_64
/usr/include/linux/memfd.h has

> #define MFD_HUGE_16GB	HUGETLB_FLAG_ENCODE_16GB

and /usr/include/asm-generic/hugetlb_encode.h has

> #define HUGETLB_FLAG_ENCODE_16GB	(34 << HUGETLB_FLAG_ENCODE_SHIFT)

For another (and as predicted in 29d47d22c43e6adc1850b7db5880028dcd07d1b3 "Fix
passing --disable-optimized into external/python3": "in a Linux UBsan build,
making ExternalProject_python3 would have started to cause some 'applying zero
offset to null pointer' failures, but which would have been easy to fix"),
silence

> Objects/listobject.c:551:24: runtime error: applying zero offset to null pointer
>  #0 in list_concat at workdir/UnpackedTarball/python3/Objects/listobject.c:551:24

Change-Id: I0523cd35e393000c8e67629a0522b2db1d8c16f0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/106984
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
(cherry picked from commit 1657639d5e405c6e1e988d51a1f267c378c74b53)
(cherry picked from commit 47a13bab80a9742d8751710ecd2f680386ea0c62)

0 files changed, 0 insertions, 0 deletions