Revert "[SLP]Initial support for copyable elements (non-schedulable only)"
This reverts commit e202dba288edd47f1b370cc43aa8cd36a924e7c1 to try to
resolve compile time issues, reported in https://llvm-compile-time-tracker.com/compare.php?from=36089e5d983fe9ae00f497c2d500f37227f82db1&to=e202dba288edd47f1b370cc43aa8cd36a924e7c1&stat=instructions%3Au&details=on