Auto merge of #37278 - matklad:lone-lifetime, r=jseyfried

Fix syntax error in the compiler

Currently `rustc` accepts the following code: `fn f<'a>() where 'a {}`. This should be a syntax error, shouldn't it?

Not sure if my changes actually compile, waiting for the LLVM to build.

src/librustc_borrowck/borrowck/mir/dataflow/graphviz.rs

@@ -88,7 +88,7 @@ pub trait MirWithFlowState<'tcx> {
 }
 
 impl<'a, 'tcx: 'a, BD> MirWithFlowState<'tcx> for MirBorrowckCtxtPreDataflow<'a, 'tcx, BD>
-    where 'a, 'tcx: 'a, BD: BitDenotation<Ctxt=MoveDataParamEnv<'tcx>>
+    where 'tcx: 'a, BD: BitDenotation<Ctxt=MoveDataParamEnv<'tcx>>
 {
     type BD = BD;
     fn node_id(&self) -> NodeId { self.node_id }

src/libsyntax/parse/parser.rs

@@ -4409,7 +4409,7 @@ impl<'a> Parser<'a> {
                     let bounded_lifetime =
                         self.parse_lifetime()?;
 
-                    self.eat(&token::Colon);
+                    self.expect(&token::Colon)?;
 
                     let bounds =
                         self.parse_lifetimes(token::BinOp(token::Plus))?;

src/test/parse-fail/where-clauses-no-bounds-or-predicates.rs

@@ -1,4 +1,4 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -20,5 +20,8 @@ fn equal2<T>(_: &T, _: &T) -> bool where T: {
     true
 }
 
+fn foo<'a>() where 'a {}
+//~^ ERROR expected `:`, found `{`
+
 fn main() {
 }