graphics/photoflow: fix build on GCC architectures, don't optimize for builder CPU

[pkubaj]

Summary

This port passes -march flags which are bad for users using packages.

Also merge https://github.com/aferrero2707/PhotoFlow/commit/0c79ee254eab9e4a44c7aeca9e43dc7990f14dd8#diff-2d5c4ed90f403ec79d56bb0af37dac07 and https://github.com/aferrero2707/PhotoFlow/commit/84c19b68d7a38dcf4877e7762303fb1841f33d3b#diff-2d5c4ed90f403ec79d56bb0af37dac07 for compatibility with GCC 9.

PR: 239833

[mat]

graphics/photoflow/Makefile

33 ↗

(On Diff #60865)

What does this do exactly?

[pkubaj]

graphics/photoflow/Makefile

33 ↗

(On Diff #60865)

Without this enabled, some staticly linked dependencies are optimized by default to the host CPU.

Since it's fine to do it when installing manually from the ports tree, I only disable it when using Poudriere.

[mat]

graphics/photoflow/Makefile

33 ↗

(On Diff #60865)

Then please add a comment saying so.

[pkubaj]

Add a comment with explanation.