Windows CI

Add `Crystal.once_init` replacing `__crystal_once_init` #15105

Sign in to view logs

Run time

Learn about OS pricing on GitHub Actions

Job	Run time
x86_64-windows-libs	1m 24s
x86_64-windows-dlls	1m 17s
x86_64-windows-llvm-dlls	26s
x86_64-windows-llvm-libs	19s
x86_64-windows-release / build	10m 27s
x86_64-windows-test	29m 27s
x86_64-windows-installer	0s
x86_64-windows-test-interpreter	6m 2s
	49m 22s