Fix bug in memref-signed-byte-64.
Fix bug in memref-signed-byte-64.

AugustusHuang/Mezzano,froggey/Mezzano,froggey/Mezzano,rvedam/Mezzano,varjagg/Mezzano,varjagg/Mezzano,rvedam/Mezzano,AugustusHuang/Mezzano