Fixed hang when comment was on the last line of the file

hcl/parser/parser_test.go

@@ -231,6 +231,10 @@ func TestParse(t *testing.T) {
 			"comment.hcl",
 			false,
 		},
+		{
+			"comment_lastline.hcl",
+			false,
+		},
 		{
 			"comment_single.hcl",
 			false,

hcl/parser/test-fixtures/comment_lastline.hcl

@@ -0,0 +1 @@
+#foo

hcl/scanner/scanner.go

@@ -224,10 +224,12 @@ func (s *Scanner) scanComment(ch rune) {
 	// single line comments
 	if ch == '#' || (ch == '/' && s.peek() != '*') {
 		ch = s.next()
-		for ch != '\n' && ch >= 0 {
+		for ch != '\n' && ch >= 0 && ch != eof {
 			ch = s.next()
 		}
-		s.unread()
+		if ch != eof && ch >= 0 {
+			s.unread()
+		}
 		return
 	}