Migrate `rvalue` and `coercion` module to use StableMIR #5924

Job	Run time
perf	2m 30s
write-json-symtab-regression	2m 58s
benchcomp-tests	3m 30s
bookrunner	2m 56s
regression (macos-12)	2m 6s
regression (ubuntu-20.04)	2m 4s
regression (ubuntu-22.04)	2m 2s
	18m 6s

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