Fix arguments passing in MethodDescCallSite::CallTargetWorker on wasm

src/coreclr/vm/callhelpers.cpp

@@ -536,7 +536,7 @@ void MethodDescCallSite::CallTargetWorker(const ARG_SLOT *pArguments, ARG_SLOT *
     callDescrData.fpReturnSize = fpReturnSize;
     callDescrData.pTarget = m_pCallTarget;
 #ifdef TARGET_WASM
-    callDescrData.nArgsSize = m_argIt.GetArgSize();
+    callDescrData.nArgsSize = nStackBytes;
 #endif // TARGET_WASM
 
     CallDescrWorkerWithHandler(&callDescrData);

src/coreclr/vm/wasm/cgencpu.h

@@ -22,8 +22,8 @@
 
 inline unsigned StackElemSize(unsigned parmSize, bool isValueType = false /* unused */, bool isFloatHfa = false /* unused */)
 {
-    _ASSERTE("The function is not implemented on wasm");
-    return 0;
+    const unsigned stackSlotSize = 4;
+    return ALIGN_UP(parmSize, stackSlotSize);
 }
 
 inline TADDR GetSP(const T_CONTEXT * context)