Revert "CallGraphSCCPass: iterate over all functions."

This reverts commit r336419: use-after-free on CallGraph::FunctionMap elements
due to the use of a stale iterator in CGPassManager::runOnModule.

The iterator may be invalidated if a pass removes a function, ex.:
  llvm::LegacyInlinerBase::inlineCalls
  inlineCallsImpl
  llvm::CallGraph::removeFunctionFromModule

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337018 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed