interpreter: Add a way to copy and environment object
interpreter: Add a way to copy and environment object

It is really usefull when you have common variables defined
for all tests and then need to set some extra ones for each test

jeandet/meson,aaronp24/meson,rhd/meson,mesonbuild/meson,ernestask/meson,ernestask/meson,wberrier/meson,thiblahute/meson,thiblahute/meson,becm/meson,pexip/meson,rhd/meson,jpakkane/meson,QuLogic/meson,QuLogic/meson,jpakkane/meson,trhd/meson,centricular/meson,MathieuDuponchelle/meson,MathieuDuponchelle/meson,MathieuDuponchelle/meson,pexip/meson,becm/meson,mesonbuild/meson,fmuellner/meson,thiblahute/meson,becm/meson,pexip/meson,jpakkane/meson,jpakkane/meson,MathieuDuponchelle/meson,ernestask/meson,fmuellner/meson,mesonbuild/meson,QuLogic/meson,aaronp24/meson,thiblahute/meson,thiblahute/meson,centricular/meson,fmuellner/meson,centricular/meson,wberrier/meson,QuLogic/meson,jeandet/meson,QuLogic/meson,wberrier/meson,centricular/meson,becm/meson,fmuellner/meson,QuLogic/meson,centricular/meson,rhd/meson,wberrier/meson,ernestask/meson,pexip/meson,fmuellner/meson,centricular/meson,aaronp24/meson,ernestask/meson,centricular/meson,becm/meson,pexip/meson,becm/meson,trhd/meson,aaronp24/meson,jeandet/meson,pexip/meson,wberrier/meson,aaronp24/meson,QuLogic/meson,trhd/meson,becm/meson,pexip/meson,thiblahute/meson,aaronp24/meson,becm/meson,ernestask/meson,pexip/meson,aaronp24/meson,MathieuDuponchelle/meson,rhd/meson,rhd/meson,mesonbuild/meson,QuLogic/meson,thiblahute/meson,centricular/meson,aaronp24/meson,rhd/meson,MathieuDuponchelle/meson,jpakkane/meson,trhd/meson,trhd/meson,rhd/meson,MathieuDuponchelle/meson,wberrier/meson,jpakkane/meson,mesonbuild/meson,fmuellner/meson,jeandet/meson,jpakkane/meson,ernestask/meson,wberrier/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,jeandet/meson,fmuellner/meson,jeandet/meson,becm/meson,trhd/meson,jeandet/meson,trhd/meson,ernestask/meson,jpakkane/meson,fmuellner/meson,jeandet/meson,pexip/meson,mesonbuild/meson,aaronp24/meson,becm/meson,rhd/meson,trhd/meson,MathieuDuponchelle/meson,QuLogic/meson,ernestask/meson,pexip/meson,fmuellner/meson,trhd/meson,thiblahute/meson,wberrier/meson,jpakkane/meson,mesonbuild/meson,thiblahute/meson,jeandet/meson,MathieuDuponchelle/meson