GDCs emitted code is crazy fast

[James Blachly]

I got around to finally compiling my project (processing high throughput 
sequencing data) and found GDC compiled code executed TWICE as fast as 
LDC compiled code, which itself was faster than DMD. I am truly surprised.

Can't test all my code yet as GDC 8.3.0 doesn't include support for 
assoc array require. I hope that there are plans for convenient binary 
installs (rather than through package managers which tend to be 
outdated, and cannot be installed on managed systems) as there are with 
DMD and LDC.

Kudos to the GDC team.