jextract error when string contains newline character

[sundararajan.athijegannathan at oracle.com]

Hi Michael,

This is in response to 
https://mail.openjdk.java.net/pipermail/panama-dev/2020-September/010830.html

This issue is fixed now: 
https://mail.openjdk.java.net/pipermail/panama-dev/2020-September/010862.html

Thanks,

-Sundar