https://bugs.winehq.org/show_bug.cgi?id=52393
--- Comment #40 from labre@posteo.de --- Using -O0 instead of the default -O2 with custom-cflags USE flag does not fix it either. Here are the flags of that compilation.
x86_64-pc-linux-gnu-gcc -m32 -c -o dllfunc.o /var/tmp/portage/app-emulation/wine-vanilla-9999/work/wine-9999/dll s/strmbase/dllfunc.c \ -I. -I/var/tmp/portage/app-emulation/wine-vanilla-9999/work/wine-9999/dlls/strmbase \ -I../../include -I/var/tmp/portage/app-emulation/wine-vanilla-9999/work/wine-9999/include \
-I/var/tmp/portage/app-emulation/wine-vanilla-9999/work/wine-9999/include/msvcrt -D__WINESRC__ \ -D_REENTRANT -fno-PIC -fno-builtin -fshort-wchar -Wall -pipe -fcf-protection=none \ -fno-stack-protector -fno-tree-loop-distribute-patterns -fno-strict-aliasing \ -Wdeclaration-after-statement -Wempty-body -Wignored-qualifiers -Wno-packed-not-aligned \ -Wshift-overflow=2 -Wstrict-prototypes -Wtype-limits -Wunused-but-set-parameter -Wvla \ -Wwrite-strings -Wpointer-arith -Wlogical-op -fno-omit-frame-pointer -march=x86-64 -pipe -O0