Qualify a call to has(FloatRegister) inside SpecializedRegSet to avoid a gcc ICE that seems to randomly manifest from time to time. No bug, r=me as trivial

--HG--
extra : rebase_source : b9bc2e779153329251fa86d1754de9760bd38689

js/src/jit/RegisterSets.h

@@ -920,7 +920,7 @@ class SpecializedRegSet<Accessors, RegisterSet> : public Accessors
         takeUnchecked(reg);
     }
     void take(FloatRegister reg) {
-        MOZ_ASSERT(has(reg));
+        MOZ_ASSERT(this->has(reg));
         takeUnchecked(reg);
     }
     void take(AnyRegister reg) {