Breaking in `while` and `for` is ignored in slice

[Ellpeck]

assertSliced(label('Break immediately', [...caps, 'name-normal', ...OperatorDatabase['<-'].capabilities, 'numbers', 'semicolons', 'newlines', 'break', 'unnamed-arguments']),
					shell, `x <- 1
${loop} {
   x <- 2;
   break
}
print(x)`, ['6@x'], 'x <- 2\nx')

with loop set to while(TRUE) or for(i in 1:100) slices incorrectly

#800

[Ellpeck]

Also true for related tests, see 31727a8

[EagleoutIce]

For now, we assume this to be correct as we do not have to be smart enough to detect, that the loop is always executed only once. This is up to abstract interpretation to figure out.