Use TypedInteger for BindGroupIndex

Bug: dawn:442
Change-Id: I889a943cbaf2d349c31a15fdf126d66964bdd0a7
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/23247
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Stephen White <senorblanco@chromium.org>

src/common/HashUtils.h

@@ -17,6 +17,7 @@
 
 #include "common/Platform.h"
 #include "common/TypedInteger.h"
+#include "common/ityp_bitset.h"
 
 #include <bitset>
 #include <functional>
@@ -87,4 +88,14 @@ size_t Hash(const std::bitset<N>& value) {
 }
 #endif
 
+namespace std {
+    template <typename Index, size_t N>
+    class hash<ityp::bitset<Index, N>> {
+      public:
+        size_t operator()(const ityp::bitset<Index, N>& value) const {
+            return Hash(static_cast<const std::bitset<N>&>(value));
+        }
+    };
+}  // namespace std
+
 #endif  // COMMON_HASHUTILS_H_

src/common/TypedInteger.h

@@ -62,12 +62,14 @@ using TypedInteger = T;
 
 namespace detail {
     template <typename Tag, typename T>
-    class TypedIntegerImpl {
+    class alignas(T) TypedIntegerImpl {
         static_assert(std::is_integral<T>::value, "TypedInteger must be integral");
         T mValue;
 
       public:
         constexpr TypedIntegerImpl() : mValue(0) {
+            static_assert(alignof(TypedIntegerImpl) == alignof(T), "");
+            static_assert(sizeof(TypedIntegerImpl) == sizeof(T), "");
         }
 
         // Construction from non-narrowing integral types.

src/common/ityp_bitset.h

@@ -58,6 +58,14 @@ namespace ityp {
         using Base::none;
         using Base::size;
 
+        bool operator==(const bitset& other) const noexcept {
+            return Base::operator==(static_cast<const Base&>(other));
+        }
+
+        bool operator!=(const bitset& other) const noexcept {
+            return Base::operator!=(static_cast<const Base&>(other));
+        }
+
         bitset& operator&=(const bitset& other) noexcept {
             return static_cast<bitset&>(Base::operator&=(static_cast<const Base&>(other)));
         }
@@ -117,6 +125,8 @@ namespace ityp {
         friend BitSetIterator<N, Index> IterateBitSet(const bitset& bitset) {
             return BitSetIterator<N, Index>(static_cast<const Base&>(bitset));
         }
+
+        friend class std::hash<bitset>;
     };
 
 }  // namespace ityp