fmt: keep the shebang header in vsh files (#7893)

vlib/v/fmt/fmt.v

@@ -1355,6 +1355,10 @@ struct CommentsOptions {
 }
 
 pub fn (mut f Fmt) comment(node ast.Comment, options CommentsOptions) {
+	if node.text.starts_with('#!') {
+		f.writeln(node.text)
+		return
+	}
 	if options.iembed {
 		x := node.text.trim_left('\x01')
 		if x.contains('\n') {

vlib/v/fmt/tests/vscript_keep.vv

@@ -0,0 +1,4 @@
+#!/usr/local/bin/v run
+
+x := 5
+println(x)

vlib/v/scanner/scanner.v

@@ -820,9 +820,9 @@ fn (mut s Scanner) text_scan() token.Token {
 				s.ignore_line()
 				if nextc == `!` {
 					// treat shebang line (#!) as a comment
-					s.line_comment = s.text[start + 1..s.pos].trim_space()
+					comment := s.text[start - 1..s.pos].trim_space()
 					// s.fgenln('// shebang line "$s.line_comment"')
-					continue
+					return s.new_token(.comment, comment, comment.len + 2)
 				}
 				hash := s.text[start..s.pos].trim_space()
 				return s.new_token(.hash, hash, hash.len)