skip empty LN with # instead of filling LN

[gapkalov]

gcc pack more than six sequent empty line into one line with using of # directive like this one:

before:
\r
\r
\r
\r
\r
\r
void foo(){}
after:
# 6 "filename.ext"
void foo(){}

https://gcc.gnu.org/onlinedocs/cpp/Preprocessor-Output.html

this is dramatically decrease size of output file

[shevek]

Very good idea, and somewhat artfully chosen. #line directives were a pain in the [....] and I'll spend a bit more time on this.