-Werror=stringop-overflow -O3 returns false-positives on ppc64el

I have seen various ppc64el-specific build failures in lunar because of use of -Werror + -O3 and -Wstringop-overflow returing false positive results. E.g.:

[...]
mme_context.c: In function ‘mme_context_parse_config’:
mme_context.c:1237:66: error: writing 16 bytes into a region of size 5 [-Werror=stringop-overflow=]
 1237 | network_full_name->name[(i*2)+1] =
      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
 1238 | c_network_name[i];
      | ~~~~~~~~~~~~~~~~~
mme_context.c:29:22: note: at offset 804187 into destination object ‘self’ of size 804192
   29 | static mme_context_t self;
      | ^~~~
mme_context.c:1237:66: error: writing 16 bytes into a region of size 0 [-Werror=stringop-overflow=]
 1237 | network_full_name->name[(i*2)+1] =
      | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
 1238 | c_network_name[i];
      | ~~~~~~~~~~~~~~~~~
mme_context.c:29:22: note: at offset 804203 into destination object ‘self’ of size 804192
   29 | static mme_context_t self;
      | ^~~~
[...]

https://launchpad.net/ubuntu/+source/nextepc/0.3.10+nods-4.2/+build/24633802

There is no object of size 804192 here and these offsets appear to be fabricated out of whole cloth.