better diagnostics for eof in a string. this assumes that embedded newlines are legal in back-quote strings.
better diagnostics for eof in a string.
this assumes that embedded newlines are
legal in back-quote strings.

R=r
OCL=30502
CL=30502
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go