Don't insert receiver NULL checks on GNUStep #2280

Job	Run time
Check MSRV	1m 53s
Check MSRV	1m 53s
Lint macOS 64bit	4m 0s
Lint macOS 64bit	4m 0s
Check formatting	17s
Check formatting	17s
Lint iOS 32bit	1m 15s
Lint iOS 32bit	1m 15s
Lint GNUStep + exceptions	1m 37s
Lint GNUStep + exceptions	1m 37s
Lint header-translator	37s
Lint header-translator	37s
Lint test-assembly	39s
Lint test-assembly	39s
Test macOS 12	6m 20s
Test macOS 12	6m 20s
Check icrate features	16m 9s
Check icrate features	16m 9s
Verify header translator output	1m 13s
Verify header translator output	1m 13s
Assembly tests	4m 45s
Assembly tests	4m 45s
Test macOS 11	9m 41s
Test macOS 11	9m 41s
Test Compiler-RT	57s
Test Compiler-RT	57s
Build macOS AArch64	13m 20s
Build macOS AArch64	13m 20s
Test GNUStep with libobjc2 v1.9	5m 15s
Test GNUStep with libobjc2 v1.9	5m 15s
Test on iOS simulator w. dinghy	11m 12s
Test on iOS simulator w. dinghy	11m 12s
Test GNUStep with libobjc2 v2.0	5m 23s
Test GNUStep with libobjc2 v2.0	5m 23s
Test macOS old SDK	8m 20s
Test macOS old SDK	8m 20s
Compiler UI	2m 0s
Compiler UI	2m 0s
Test GNUStep with libobjc2 v2.1 on nightly	5m 10s
Test GNUStep with libobjc2 v2.1 on nightly	1s
Test macOS nightly	11m 2s
Test macOS nightly	11m 2s
Test GNUStep 32bit	5m 3s
Test GNUStep 32bit	5m 3s
Build macOS 32bit	12m 19s
Build macOS 32bit	12m 19s
Build iOS simulator ARM64	3m 38s
Build iOS simulator ARM64	3m 38s
Build iOS ARM64	3m 36s
Build iOS ARM64	3m 36s
Build iOS ARMv7	6m 7s
Build iOS ARMv7	6m 7s
Build iOS ARMv7s	5m 47s
Build iOS ARMv7s	5m 47s
Build iOS 32bit x86	6m 40s
Build iOS 32bit x86	6m 40s
	5h 3m 21s

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