CRAN san checking issue on generated code on Windows only

[perrydv]

We have a report that the nimbleFunction line

xPrev     = nimNumeric(length=lengthOri, value=x[1:lengthOri])

where x is an argument, and the compileNimble call is in a package vignette, gives the following error on Windows only:

File: build_vignettes.log
/home/hornik/tmp/CRAN_special_gcc-san/Library/nimble/include/nimble/nimbleEigenNimArr.h:244:11: runtime error: null pointer passed as argument 1, which is declared to never be null
/home/hornik/tmp/CRAN_special_gcc-san/Library/nimble/include/nimble/nimbleEigenNimArr.h:244:11: runtime error: null pointer passed as argument 2, which is declared to never be null

It doesn't appear that those arguments should be null pointers. I suggested the user work around the error by the more direct

xPrev = x[1:lengthOri]

but nevertheless I want to record this for future reference and possible clean-up.