Derive hash for BitSet and BitMatrix

Author: tmiasko

compiler/rustc_index/src/bit_set.rs

@@ -87,7 +87,7 @@ macro_rules! bit_relations_inherent_impls {
 /// to or greater than the domain size. All operations that involve two bitsets
 /// will panic if the bitsets have differing domain sizes.
 ///
-#[derive(Eq, PartialEq, Decodable, Encodable)]
+#[derive(Eq, PartialEq, Hash, Decodable, Encodable)]
 pub struct BitSet<T> {
     domain_size: usize,
     words: Vec<Word>,
@@ -987,7 +987,7 @@ impl<T: Idx> GrowableBitSet<T> {
 ///
 /// All operations that involve a row and/or column index will panic if the
 /// index exceeds the relevant bound.
-#[derive(Clone, Eq, PartialEq, Decodable, Encodable)]
+#[derive(Clone, Eq, PartialEq, Hash, Decodable, Encodable)]
 pub struct BitMatrix<R: Idx, C: Idx> {
     num_rows: usize,
     num_columns: usize,