Instrument validity checks for pointer to reference casts for slices and str's #8277

Job	Run time
benchcomp-tests	3m 50s
documentation	2m 3s
perf	33m 11s
regression (macos-13)	51m 28s
write-json-symtab-regression	17m 37s
regression (ubuntu-20.04)	28m 58s
regression (ubuntu-22.04)	31m 27s
regression (macos-14)	30m 23s
	3h 18m 57s

Provide feedback