Revert "NFC: static_assert instead of comment"

This reverts commit fa36fcff16c7d4f78204d6296bf96c3558a4a672.

Causes the following Windows failure:

  C:\Buildbot\Slave\llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast\llvm.src\lib\CodeGen\MachineInstr.cpp(762):
  error C2338: must be trivially copyable to memmove

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264516 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed