Add lang items for ranges.

Author: nrc

src/libcore/ops.rs

@@ -882,9 +882,11 @@ macro_rules! countable_impl(
 countable_impl!(uint u8 u16 u32 u64 int i8 i16 i32 i64)
 
 /// An unbounded range.
+#[lang="full_range"]
 pub struct FullRange;
 
 /// A range which i bounded at both ends.
+#[lang="range"]
 pub struct Range<Idx> {
     /// The lower bound of the range (inclusive).
     pub start: Idx,
@@ -926,6 +928,7 @@ impl<Idx: Clone + Countable> DoubleEndedIterator<Idx> for Range<Idx> {
 }
 
 /// A range which is only bounded below.
+#[lang="range_from"]
 pub struct RangeFrom<Idx> {
     /// The lower bound of the range (inclusive).
     pub start: Idx,

src/librustc/middle/lang_items.rs

@@ -267,6 +267,9 @@ lets_do_this! {
     IndexMutTraitLangItem,           "index_mut",               index_mut_trait;
     SliceTraitLangItem,              "slice",                   slice_trait;
     SliceMutTraitLangItem,           "slice_mut",               slice_mut_trait;
+    RangeStructLangItem,             "range",                   range_struct;
+    RangeFromStructLangItem,         "range_from",              range_from_struct;
+    FullRangeStructLangItem,         "full_range",              full_range_struct;
 
     UnsafeTypeLangItem,              "unsafe",                  unsafe_type;