build(darwin): add GNU env support #176

Job	Run time
iOS (audio libs)	3m 56s
iOS (audio libs)	3m 56s
Android	4m 40s
Android	4m 40s
Android (audio libs)	4m 38s
Android (audio libs)	4m 38s
Linux (audio libs)	1m 18s
Linux (audio libs)	1m 18s
macOS (audio libs)	4m 38s
macOS (audio libs)	4m 38s
iOS	6m 32s
iOS	6m 32s
Linux	2m 25s
Linux	2m 25s
Windows (audio libs)	4m 1s
Windows (audio libs)	4m 1s
macOS	4m 2s
macOS	4m 2s
package:media_kit tests (Linux)	36m 25s
package:media_kit tests (Linux)	36m 25s
package:media_kit tests (macOS)	36m 42s
package:media_kit tests (macOS)	36m 37s
package:media_kit tests (Web)	31m 16s
package:media_kit tests (Web)	31m 16s
package:media_kit tests (Windows)	37m 47s
package:media_kit tests (Windows)	37m 47s
Android (optional libs)	5m 9s
Android (optional libs)	5m 9s
iOS (optional libs)	3m 47s
iOS (optional libs)	3m 47s
Linux (optional libs)	1m 13s
Linux (optional libs)	1m 13s
macOS (optional libs)	3m 35s
macOS (optional libs)	3m 35s
Windows (optional libs)	5m 6s
Windows (optional libs)	5m 6s
Windows	4m 29s
Windows	4m 29s
	6h 43m 13s

Provide feedback