MachineScheduler: Make some GenericScheduler member variables protected
MachineScheduler: Make some GenericScheduler member variables protected

Summary: We will need these in AMDGPU's new SchedStrategy implmentation.

Reviewers: MatzeB, atrick

Subscribers: llvm-commits, MatzeB

Differential Revision: https://reviews.llvm.org/D23679

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@279270 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm