blockfreq: Expose getPackagedNode()

Make `getPackagedNode()` a member function of
`BlockFrequencyInfoImplBase` so that it's available for templated code.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207183 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed