Bug 1645820 - Mark MWasmStackResult as being a call result capture r=lth

Flag was missing, as MWasmStackResult doesn't inherit from
MWasmResultBase.

Depends on D79698

Differential Revision: https://phabricator.services.mozilla.com/D79699

js/src/jit/MIR.h

@@ -12315,6 +12315,7 @@ class MWasmStackResult : public MUnaryInstruction, public NoTypePolicy::Data {
   MWasmStackResult(MWasmStackResultArea* resultArea, size_t idx)
       : MUnaryInstruction(classOpcode, resultArea), resultIdx_(idx) {
     setResultType(result().type());
+    setCallResultCapture();
   }
 
  public: