Use SEQ-CST ordering to match ECMAScript

Author: MattiasBuelens

index.bs

@@ -9332,17 +9332,17 @@ a reference to the same object that the IDL value represents.
         1.  If |jsBufferSource| has a \[[TypedArrayName]] [=/internal slot=]:
             1.  Assert: |jsBufferSource| is a [=typed array type=] instance.
             1.  Let |taRecord| be [$MakeTypedArrayWithBufferWitnessRecord$](|jsBufferSource|,
-                Unordered).
+                Seq-Cst).
             1.  Return [$TypedArrayByteLength$](|taRecord|).
         1.  Otherwise:
             1.  Assert: |jsBufferSource| is a {{DataView}}.
             1.  Let |viewRecord| be [$MakeDataViewWithBufferWitnessRecord$](|jsBufferSource|,
-                Unordered).
+                Seq-Cst).
             1.  If [$IsViewOutOfBounds$](|viewRecord|) is true, return 0.
             1.  Return [$GetViewByteLength$](|viewRecord|).
     1.  Otherwise, if [$IsSharedArrayBuffer$](|jsBufferSource|) is true, then:
         1.  Assert: |jsBufferSource| is a {{SharedArrayBuffer}}.
-        1.  Return [$ArrayBufferByteLength$](|jsBufferSource|, Unordered).
+        1.  Return [$ArrayBufferByteLength$](|jsBufferSource|, Seq-Cst).
     1.  Otherwise:
         1.  Assert: |jsBufferSource| is an {{ArrayBuffer}}.
         1.  Return |jsBufferSource|.\[[ArrayBufferByteLength]].