(multiline_string_line): New file scope static variable.

(multiline_string_line): New file scope static variable.

(rescan): Delete multiline_string_line variable definition.
(skip_quoted_string): Print start line number of unterminated
string and character constants.  When see a newline: warn if
pedantic; delete unreachable duplicate code for traditional case;
set multiline_string_line.

From-SVN: r3012