Fix crash when parsing multiline CRLF comment (projectfluent#302)

Author: JasperDeSutter

fluent-syntax/src/parser/comment.rs

@@ -31,7 +31,7 @@ where
 
             if self.ptr == self.length {
                 break;
-            } else if self.is_current_byte(b'\n') {
+            } else if self.is_eol() {
                 content.push(self.get_comment_line());
             } else {
                 if let Err(e) = self.expect_byte(b' ') {
@@ -52,7 +52,7 @@ where
 
     pub(super) fn skip_comment(&mut self) {
         loop {
-            while self.ptr < self.length && !self.is_current_byte(b'\n') {
+            while self.ptr < self.length && !self.is_eol() {
                 self.ptr += 1;
             }
             self.ptr += 1;

fluent-syntax/tests/fixtures/crlf.ftl

@@ -1,4 +1,7 @@
 
+# Term Comment
+# with a blank last line.
+#
 key01 = Value 01
 key02 =
 

fluent-syntax/tests/fixtures/crlf.json

@@ -17,7 +17,10 @@
                 ]
             },
             "attributes": [],
-            "comment": null
+            "comment": {
+                "type": "Comment",
+                "content": "Term Comment\nwith a blank last line.\n"
+            }
         },
         {
             "type": "Message",