compilers: Debug optimization level should be -O0 (#509)
compilers: Debug optimization level should be -O0 (#509)

Without any -O options, gcc does not generate properly debuggable code.



> With no -O option at all, some compiler passes that collect information useful

> for debugging do not run at all



gcc recommends -Og, but that isn't supported by clang, so we use -O0



See https://github.com/mesonbuild/meson/pull/509 for more discussion
becm/meson,becm/meson,fmuellner/meson,thiblahute/meson,jeandet/meson,ernestask/meson,rhd/meson,rhd/meson,germandiagogomez/meson,thiblahute/meson,mesonbuild/meson,fmuellner/meson,QuLogic/meson,aaronp24/meson,jpakkane/meson,pexip/meson,trhd/meson,ernestask/meson,pexip/meson,germandiagogomez/meson,MathieuDuponchelle/meson,wberrier/meson,mesonbuild/meson,mesonbuild/meson,thiblahute/meson,becm/meson,MathieuDuponchelle/meson,jpakkane/meson,thiblahute/meson,aaronp24/meson,QuLogic/meson,jpakkane/meson,QuLogic/meson,wberrier/meson,aaronp24/meson,jeandet/meson,becm/meson,MathieuDuponchelle/meson,jeandet/meson,jpakkane/meson,fmuellner/meson,becm/meson,fmuellner/meson,rhd/meson,rhd/meson,aaronp24/meson,centricular/meson,mesonbuild/meson,fmuellner/meson,MathieuDuponchelle/meson,thiblahute/meson,pexip/meson,germandiagogomez/meson,centricular/meson,wberrier/meson,ernestask/meson,QuLogic/meson,germandiagogomez/meson,aaronp24/meson,thiblahute/meson,wberrier/meson,wberrier/meson,trhd/meson,mesonbuild/meson,MathieuDuponchelle/meson,germandiagogomez/meson,jpakkane/meson,ernestask/meson,centricular/meson,mesonbuild/meson,becm/meson,trhd/meson,jeandet/meson,wberrier/meson,jeandet/meson,wberrier/meson,trhd/meson,pexip/meson,centricular/meson,centricular/meson,trhd/meson,pexip/meson,MathieuDuponchelle/meson,aaronp24/meson,jpakkane/meson,QuLogic/meson,thiblahute/meson,fmuellner/meson,QuLogic/meson,jpakkane/meson,becm/meson,QuLogic/meson,MathieuDuponchelle/meson,ernestask/meson,jeandet/meson,fmuellner/meson,aaronp24/meson,rhd/meson,ernestask/meson,pexip/meson,germandiagogomez/meson,rhd/meson,trhd/meson,trhd/meson,becm/meson,jeandet/meson,thiblahute/meson,jeandet/meson,fmuellner/meson,ernestask/meson,MathieuDuponchelle/meson,centricular/meson,mesonbuild/meson,QuLogic/meson,jpakkane/meson,ernestask/meson,pexip/meson,rhd/meson,aaronp24/meson,rhd/meson,centricular/meson,aaronp24/meson,jpakkane/meson,wberrier/meson,trhd/meson,pexip/meson,centricular/meson,mesonbuild/meson,becm/meson,becm/meson,pexip/meson,jeandet/meson,mesonbuild/meson,fmuellner/meson,QuLogic/meson,thiblahute/meson,mesonbuild/meson,ernestask/meson,germandiagogomez/meson,MathieuDuponchelle/meson,trhd/meson,pexip/meson