Build fails with -flto

[eli-schwartz]

Log excerpt:

x86_64-pc-linux-gnu-gcc -march=native -fstack-protector-all -O2 -pipe -fdiagnostics-color=always -frecord-gcc-switches -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-clash-protection -Wformat -Werror=format-security -flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing -Werror=implicit-function-declaration -Werror=implicit-int -Werror=int-conversion -Werror=incompatible-pointer-types -Wall -I../../drbd-headers -I.. -I. -I../shared   -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 -o drbdadm drbdadm_scanner.o drbdadm_parser.o drbdadm_postparse.o drbdadm_main.o drbdadm_adjust.o drbdadm_dump.o drbdtool_common.o drbdadm_usage_cnt.o drbd_buildtag.o registry.o config_flags.o libnla.o drbd_nla.o shared_tool.o shared_main.o shared_parser.o libgenl.o drbdadm_linux.o drbdtool_common_linux.o path_linux.o shared_linux.o
../shared/shared_main.c:60:22: error: type of ‘ifreq_list’ does not match original declaration [-Werror=lto-type-mismatch]
   60 | extern struct ifreq *ifreq_list;
      |                      ^
drbdadm_main.c:150:15: note: ‘ifreq_list’ was previously declared here
  150 | struct ifreq *ifreq_list = NULL;
      |               ^
drbdadm_main.c:150:15: note: code may be misoptimized unless ‘-fno-strict-aliasing’ is used
lto1: some warnings being treated as errors
lto-wrapper: fatal error: x86_64-pc-linux-gnu-gcc returned 1 exit status
compilation terminated.
/usr/libexec/gcc/x86_64-pc-linux-gnu/ld: error: lto-wrapper failed
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:111: drbdadm] Error 1

Full build log:
drbd-utils-9.25.0:20231231-225010.log

Downstream bug report: https://bugs.gentoo.org/863728