Do not reserve space for the ColdEdges and NormalEdges vectors.
Discussion and rationale at
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130520/175698.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182653 91177308-0d34-0410-b5e6-96231b3b80d8