Bug 1639563 - fix GCC internal compiler error. r=jfkthame

Differential Revision: https://phabricator.services.mozilla.com/D76508

gfx/thebes/gfxUserFontSet.cpp

@@ -173,7 +173,7 @@ const uint8_t* gfxUserFontEntry::SanitizeOpenTypeData(
     return nullptr;
   }
 
-  gfxOTSExpandingMemoryStream output(lengthHint);
+  gfxOTSExpandingMemoryStream<gfxOTSMozAlloc> output(lengthHint);
 
   gfxOTSMessageContext otsContext;
   if (!otsContext.Process(&output, aData, aLength, aMessages)) {