Bug 1290614, part 6 - Hoist out the common loop over all interfaces in XPCNativeSetKey::Hash(). r=mrbkap

Both cases first hash together all of the existing interfaces.

MozReview-Commit-ID: AnUF5uPSPpN

--HG--
extra : rebase_source : 43ac016974d3ee4dfbd92361348aeeae5b6a793c

js/xpconnect/src/XPCWrappedNativeInfo.cpp

@@ -442,14 +442,12 @@ XPCNativeSetKey::Hash() const
     } else {
         XPCNativeInterface** current = mBaseSet->GetInterfaceArray();
         uint16_t count = mBaseSet->GetInterfaceCount();
+        for (uint16_t i = 0; i < count; i++) {
+            h ^= HashPointer(*(current++));
+        }
+
         if (mAddition) {
-            for (uint16_t i = 0; i < count; i++) {
-                h ^= HashPointer(*(current++));
-            }
             h ^= HashPointer(mAddition);
-        } else {
-            for (uint16_t i = 0; i < count; i++)
-                h ^= HashPointer(*(current++));
         }
     }