Work towards a non-panicing parser (libsyntax)

- Functions in parser.rs return PResult<> rather than panicing
- Other functions in libsyntax call panic! explicitly for now if they rely on panicing behaviour.
- 'panictry!' macro added as scaffolding while converting panicing functions.
  (This does the same as 'unwrap()' but is easier to grep for and turn into try!())
- Leaves panicing wrappers for the following functions so that the
  quote_* macros behave the same:
  - parse_expr, parse_item, parse_pat, parse_arm, parse_ty, parse_stmt

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libsyntax/parse/obsolete.rs b/src/libsyntax/parse/obsolete.rs
index f120dde8e1c..3b21b5059da 100644
--- a/src/libsyntax/parse/obsolete.rs
+++ b/src/libsyntax/parse/obsolete.rs
@@ -100,7 +100,7 @@ impl<'a> ParserObsoleteMethods for parser::Parser<'a> {
 
     fn eat_obsolete_ident(&mut self, ident: &str) -> bool {
         if self.is_obsolete_ident(ident) {
-            self.bump();
+            panictry!(self.bump());
             true
         } else {
             false