Unified LTO and Fat LTO do not use the regular LTO prelink pipeline when
-flto/-flto=full is specified on the command line, thus they require
LowerMatrixIntrinsicsPass to be run during the link stage. To enable
this, we pass -enable-matrix to the LTO driver, replicating ThinLTO
behavior. This fix was applied to ThinLTO in https://reviews.llvm.org/D153583.
This fixes#77621.