[Dominators] Remove DominatorBase class
[Dominators] Remove DominatorBase class

Summary:
DominatorBase class was only used by DominatorTreeBase. It didn't provide any useful abstractions, nor simplified anything, so I see no point keeping it.

This commit removes the DominatorBase class and moves its content into DominatorTreeBase.

This is the first patch in a series that tries to make all DomTrees have a single virtual root, which will allow to further simplify code (especially when it comes to incremental updates).

Reviewers: dberlin, sanjoy, chandlerc

Reviewed By: dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34493

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@306713 91177308-0d34-0410-b5e6-96231b3b80d8

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