Add `muldiv_c` and `muxadd` peepopts #1539

Job	Run time
pre_docs_job	4s
pre_job	4s
Reusable build (ubuntu-latest)	15m 32s
Reusable build (macos-latest)	7m 16s
Try build docs (html)	1m 15s
Try build docs (latexpdf)	1m 11s
Run tests (ubuntu-latest)	10m 28s
Run tests (macos-latest)	9m 31s
Run docs tests (ubuntu-latest)	57s
	46m 18s

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