Auto merge of #51369 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Auto merge of #51369 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 7 pull requests

Successful merges:

 - #50852 (Add doc comment to hiding portions of code example)
 - #51183 (Update rustdoc book to suggest using Termination trait instead of hidden ‘foo’ function)
 - #51255 (Fix confusing error message for sub_instant)
 - #51256 (Fix crate-name option in rustdoc)
 - #51308 (Check array indices in constant propagation)
 - #51343 (test: Ignore some problematic tests on sparc and sparc64)
 - #51358 (Tests that #39963 is fixed on MIR borrowck)

Failed merges: