Add RcBlock::as_ptr and RcBlock::into_raw #3053

Job	Run time
Check formatting	8s
Lint macOS 64bit	2m 41s
Check MSRV	50s
Lint iOS 32bit	2m 12s
Lint GNUStep + exceptions	1m 26s
Lint header-translator	30s
Lint test-assembly	24s
Test macOS 12	3m 50s
Assembly tests	49s
Check framework features	0s
Verify header translator output	53s
${{ matrix.name }}	0s
Test Compiler-RT	24s
Test GNUStep with libobjc2 v1.9	1m 27s
Compiler UI	1m 37s
Test GNUStep with libobjc2 v2.0	1m 6s
Test on iOS simulator w. dinghy	0s
Test GNUStep with libobjc2 v2.1 on nightly	1m 24s
Test GNUStep 32bit	1m 14s
	20m 55s

Provide feedback