MachineScheduler: Limit the size of the ready list.

Avoid quadratic complexity in unusually large basic blocks by limiting
the size of the ready lists.

Differential Revision: http://reviews.llvm.org/D19349

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267189 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed