Recover most of the compile time regression due to recent live interval changes.
1. Eliminate the costly live interval "swapping".
2. Change ValueNumberInfo container from SmallVector to std::vector. The former
   performs slowly when the vector size is very large.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41536 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed