C++ flag -mtune=native makes oF projects not compile for iOS

[sourya-sen]

PG is adding cpp flag -mtune=native which is not supported by clang for iOS projects. Mojave 10.14.2, Xcode 10.1, iPad Pro.

The exact error is: clang: error: the clang compiler does not support '-mtune=native'

Simply taking it out of the flags for the iOS project works.

Can/should it be just removed from PG - or will it cause issues for native Mac apps? It's being generated here: https://github.com/openframeworks/projectGenerator/blob/c8ddfe81542a5d50853b8694adde3c033f36a17d/ofxProjectGenerator/src/projects/xcodeProject.cpp#L157