[X86] Add missing scheduling class tag for i64 absolute address moves

Expand existing SchedRW to encompass these like it did for the other memory offset movs - added comments to closing braces to keep track of def scopes.

We only tagged it with the itinerary class, so completeness checks were erroneously passed (PR35639).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324910 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed