Fix compilation error for assoc types in the Iterator traits

This error is the following:

```
$ make
rustc -O -o bin/racer src/main.rs
src/racer/codeiter.rs:22:10: 22:32 error: wrong number of type arguments: expected 0, found 1
src/racer/codeiter.rs:22 impl<'a> Iterator<(uint, uint)> for StmtIndicesIter<'a> {
                                  ^~~~~~~~~~~~~~~~~~~~~~
```

This is caused by rust-lang/rust#20441

src/main.rs

@@ -1,5 +1,6 @@
 #![feature(macro_rules)]
 #![feature(phase)]
+#![feature(associated_types)]
 #[phase(plugin, link)] extern crate log;
 
 extern crate syntax;

src/racer/codecleaner.rs

@@ -5,8 +5,8 @@ pub fn rejustify(src: &str) -> String {
  let mut sb = String::new();
  for l in s.lines() {
  let tabless = l.slice_from(4);
- sb.push_str(tabless); 
- if tabless.len() != 0 { 
+ sb.push_str(tabless);
+ if tabless.len() != 0 {
  sb.push_str("\n");
  }
  }
@@ -35,7 +35,9 @@ pub struct CodeIndicesIter<'a> {
  state: State
 }
 
-impl<'a> Iterator<(uint, uint)> for CodeIndicesIter<'a> {
+impl<'a> Iterator for CodeIndicesIter<'a> {
+ type Item = (uint, uint);
+
  #[inline]
  fn next(&mut self) -> Option<(uint, uint)> {
  return match self.state {

src/racer/codeiter.rs

@@ -19,7 +19,9 @@ pub struct StmtIndicesIter<'a> {
  enddelim: u8
 }
 
-impl<'a> Iterator<(uint, uint)> for StmtIndicesIter<'a> {
+impl<'a> Iterator for StmtIndicesIter<'a> {
+ type Item = (uint, uint);
+
  #[inline]
  fn next(&mut self) -> Option<(uint, uint)> {
  let semicolon: u8 = ";".as_bytes()[0];
@@ -78,10 +80,10 @@ impl<'a> Iterator<(uint, uint)> for StmtIndicesIter<'a> {
  self.start = self.pos;
  }
 
- 
+
  // if the statement starts with 'macro_rules!' then we're in a macro
  // We need to know this because a closeparen can terminate a macro
- if (self.end - self.pos) > 12 && 
+ if (self.end - self.pos) > 12 &&
  self.src.slice(self.pos, self.pos+12) == "macro_rules!" {
  self.is_macro = true;
  }
@@ -92,14 +94,14 @@ impl<'a> Iterator<(uint, uint)> for StmtIndicesIter<'a> {
 
  // macros can be terminated by closeparen if opened by one
  if self.is_macro &&
- self.bracelevel == 0 && 
+ self.bracelevel == 0 &&
  self.parenlevel == 0 {
  self.enddelim = closeparen;
  }
- 
+
  // also macro invocations can too
  if self.pos > 0 && src_bytes[self.pos-1] == bang &&
- self.bracelevel == 0 && 
+ self.bracelevel == 0 &&
  self.parenlevel == 0 {
  self.enddelim = closeparen;
  }
@@ -110,9 +112,9 @@ impl<'a> Iterator<(uint, uint)> for StmtIndicesIter<'a> {
  self.parenlevel -= 1;
 
  } else if src_bytes[self.pos] == openbrace {
- // if we are top level and stmt is not a 'use' then 
+ // if we are top level and stmt is not a 'use' then
  // closebrace finishes the stmt
- if self.bracelevel == 0 && 
+ if self.bracelevel == 0 &&
  self.parenlevel == 0 &&
  !(is_a_use_stmt(self.src, self.start, self.pos)) {
  self.enddelim = closebrace;
@@ -128,12 +130,12 @@ impl<'a> Iterator<(uint, uint)> for StmtIndicesIter<'a> {
  }
 
  // attribute #[foo = bar]
- if self.bracelevel == 0 && self.start == self.pos && 
+ if self.bracelevel == 0 && self.start == self.pos &&
  src_bytes[self.pos] == hash {
  self.enddelim = closesqbrace;
  }
 
- if self.bracelevel == 0 && self.parenlevel == 0 && 
+ if self.bracelevel == 0 && self.parenlevel == 0 &&
  src_bytes[self.pos] == self.enddelim {
  let start = self.start;
  self.start = self.pos+1;
@@ -145,24 +147,24 @@ impl<'a> Iterator<(uint, uint)> for StmtIndicesIter<'a> {
 
  self.pos += 1;
  }
- 
+
  }
  }
 }
 
 fn is_a_use_stmt(src: &str, start: uint, pos: uint) -> bool {
  let src_bytes = src.as_bytes();
  let whitespace = " {\t\r\n".as_bytes();
- (pos > 3 && src_bytes.slice(start, start+3) == "use".as_bytes() && 
- whitespace.contains(&src_bytes[start+3])) || 
+ (pos > 3 && src_bytes.slice(start, start+3) == "use".as_bytes() &&
+ whitespace.contains(&src_bytes[start+3])) ||
  (pos > 7 && src_bytes.slice(start, start+7) == "pub use".as_bytes() &&
  whitespace.contains(&src_bytes[start+7]))
 }
 
 pub fn iter_stmts<'a>(src: &'a str) -> StmtIndicesIter<'a> {
  let semicolon: u8 = ";".as_bytes()[0];
- StmtIndicesIter{src: src, it: code_chunks(src), 
- pos: 0, start: 0, end: 0, bracelevel: 0, 
+ StmtIndicesIter{src: src, it: code_chunks(src),
+ pos: 0, start: 0, end: 0, bracelevel: 0,
  parenlevel: 0, enddelim: semicolon, is_macro: false}
 }