%line: quote filenames with double spaces, use unsigned char check
%line: quote filenames with double spaces, use unsigned char check

Filenames with double spaces need to be quoted; the preprocessor will
otherwise collapse spaces into one.

When comparing for control characters and spaces, use an unsigned
compare.

Signed-off-by: H. Peter Anvin (Intel) <8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>

techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm