[turbofan] Run everything after representation selection concurrently.

src/handles.h

Index: src/handles.h
diff --git a/src/handles.h b/src/handles.h
index 1f97d6ff7e6d95c76b521baf45938e5f1c5f8243..ab8ed0920a4c637b6c0bc67775c801ee287f2ec1 100644
--- a/src/handles.h
+++ b/src/handles.h
@@ -43,6 +43,10 @@ class HandleBase {
 
   V8_INLINE bool is_null() const { return location_ == nullptr; }
 
+  // Returns the raw address where this handle is stored. This should only be
+  // used for hashing handles; do not ever try to dereference it.
+  V8_INLINE Address address() const { return bit_cast<Address>(location_); }
+
  protected:
   // Provides the C++ dereference operator.
   V8_INLINE Object* operator*() const {
@@ -132,14 +136,14 @@ class Handle final : public HandleBase {
   // Provide function object for location equality comparison.
   struct equal_to : public std::binary_function<Handle<T>, Handle<T>, bool> {
     V8_INLINE bool operator()(Handle<T> lhs, Handle<T> rhs) const {
-      return lhs.location() == rhs.location();
+      return lhs.address() == rhs.address();
     }
   };
 
   // Provide function object for location hashing.
   struct hash : public std::unary_function<Handle<T>, size_t> {
     V8_INLINE size_t operator()(Handle<T> const& handle) const {
-      return base::hash<void*>()(handle.location());
+      return base::hash<void*>()(handle.address());
     }
   };