Add `muldiv_c` and `muxadd` peepopts #1566

Job	Run time
pre_job	4s
Prepare Visual Studio build	31s
WASI build	19m 6s
Build nix flake (ubuntu-latest)	10m 55s
Build nix flake (macos-latest)	6m 41s
Visual Studio build	10m 36s
	47m 53s

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