its sentinel. This is quite a win when a function really has a basic block.
When the function is just a declaration (and stays so) the old way did not
allocate a sentinel. So this change is most beneficial when the ratio of
function definition to declaration is high. I.e. linkers etc. Incidentally
these are the most resource demanding applications, so I expect that the
reduced malloc traffic, locality and space savings outweigh the cost of
addition of two pointers to Function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65776 91177308-0d34-0410-b5e6-96231b3b80d8