Rollup of 5 pull requests

[jhpratt]

Successful merges:

• document capacity for ZST as example #136293 (document capacity for ZST as example)
• doc all differences of ptr:copy(_nonoverlapping) with memcpy and memmove #136359 (doc all differences of ptr:copy(_nonoverlapping) with memcpy and memmove)
• refactor notable_traits_button to use iterator combinators instead of for loop #136816 (refactor notable_traits_button to use iterator combinators instead of for loop)
• Misc print request handling cleanups + a centralized test for print request stability gating #138552 (Misc print request handling cleanups + a centralized test for print request stability gating)
• Make _Unwind_Action a type alias, not enum #138573 (Make _Unwind_Action a type alias, not enum)

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