Cherry-pick 2511322. rdar://122693092

    Use QualifiedNameImpl* as the hash key for Attribute
    https://bugs.webkit.org/show_bug.cgi?id=269093

    Reviewed by Chris Dumez and Yusuke Suzuki.

    Use QualifiedNameImpl* instead of QualifiedName::hash as the hasher input
    for Attribute to avoid the indirect memory loads.

    * Source/WebCore/dom/QualifiedName.h:
    (WebCore::add):

    Canonical link: https://commits.webkit.org/274411@main

Identifier: 272448.529@safari-7618-branch

Source/WebCore/dom/QualifiedName.h

@@ -126,7 +126,7 @@ inline void add(Hasher& hasher, const QualifiedName::QualifiedNameImpl& impl)
 
 inline void add(Hasher& hasher, const QualifiedName& name)
 {
-    add(hasher, *name.impl());
+    add(hasher, bitwise_cast<uintptr_t>(name.impl()));
 }
 
 extern LazyNeverDestroyed<const QualifiedName> anyName;