Bug 1278251 - corrected assign instead of compare. r=bbouvier

MozReview-Commit-ID: 4QrWu0MOzJB

--HG--
extra : rebase_source : a199cd5c0b3f06716df6c85167f444b5ff49e853

js/src/jit/x64/CodeGenerator-x64.cpp

@@ -599,11 +599,11 @@ CodeGeneratorX64::loadSimd(Scalar::Type type, unsigned numElems, const Operand&
         break;
       }
       case Scalar::Int8x16:
-        MOZ_ASSERT(numElems = 16, "unexpected partial load");
+        MOZ_ASSERT(numElems == 16, "unexpected partial load");
         masm.loadUnalignedSimd128Int(srcAddr, out);
         break;
       case Scalar::Int16x8:
-        MOZ_ASSERT(numElems = 8, "unexpected partial load");
+        MOZ_ASSERT(numElems == 8, "unexpected partial load");
         masm.loadUnalignedSimd128Int(srcAddr, out);
         break;
       case Scalar::Int8: