Backport rust-lang/rust#134117 and allow only `<*T>::offset`-like "GEPs". #636

Job	Run time
Test (ubuntu-24.04)	2m 42s
cargo-deny	57s
Lint	4m 42s
Android (ubuntu-24.04, aarch64-linux-android)	4m 40s
Compiletest (ubuntu-24.04)	2m 53s
Test (macOS-latest)	2m 25s
Compiletest (macOS-latest)	46s
Difftest (ubuntu-24.04)	4m 38s
Difftest (macOS-latest)	3m 31s
Test (windows-2022)	1s
Compiletest (windows-2022)	2m 5s
Difftest (windows-2022)	4m 34s
test_success	3s
	33m 57s

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