isReachableFromEntry() is not suitable for post dominator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37562 91177308-0d34-0410-b5e6-96231b3b80d8

lib/VMCore/Dominators.cpp

@@ -325,6 +325,8 @@ void DominatorTreeBase::updateDFSNumbers()
 /// isReachableFromEntry - Return true if A is dominated by the entry
 /// block of the function containing it.
 const bool DominatorTreeBase::isReachableFromEntry(BasicBlock* A) {
+  assert (!isPostDominator() 
+          && "This is not implemented for post dominators");
   return dominates(&A->getParent()->getEntryBlock(), A);
 }