games-emulation/dolphin: fix crash on pie-by-default profiles

games-emulation/dolphin: fix crash on pie-by-default profiles

Disable PIE-compatible code generation via CXXFLAGS+=-fno-pie.

Before upstream fix:
https://github.com/dolphin-emu/dolphin/commit/daa03cd1060cc826aca93a1dffc6e94bc6af6d5f
dolphin assumed executable image to be in low addresses (<2GB)
and hardcoded 32-bit absolute addresses during JIT phase.

PIE-compatible code does not have this restriction and
allows mapping binaries above 2GB area (and breaks dolphin's JIT).

Strictly speaking -no-pie (link-time flag) does not or guarantee
or require low address mapping for binary if it was already built
as PIC/PIE.

But -fno-pie imposes additional restrictions on generated code by GCC
and makes -no-pie to take effect.

We don't need this fix for live ebuild.

Closes: https://bugs.gentoo.org/640124
Package-Manager: Portage-2.3.43, Repoman-2.3.10