[AArch64] Fix order of checks in shouldScheduleAdjacent.

We need to check the opcode of FirstMI before accessing the operands. This
caused a buildbot failure during bootstrapping on AArch64.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305694 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed