add a new Region::block_iterator which actually iterates over the basic
blocks of the region.
The old iterator, now call 'block_node_iterator' iterates over
RegionNodes which contain a single basic block. This works well with the
GraphTraits-based iterator design, however most users actually want an
iterator over the BasicBlocks inside these RegionNodes. Now the
'block_iterator' is a wrapper which exposes exactly this interface.
Internally it uses the block_node_iterator to walk all nodes which are
single basic blocks, but transparently unwraps the basic block to make
user code simpler.
While this patch is a bit of a wash, most of the updates are to internal
users, not external users of the RegionInfo. I have an accompanying
patch to Polly that is a strict simplification of every user of this
interface, and I'm working on a pass that also wants the same simplified
interface.
This patch alone should have no functional impact.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156202 91177308-0d34-0410-b5e6-96231b3b80d8
A RegionPass is executed like a LoopPass but on the regions detected by the
RegionInfo pass instead of the loops detected by the LoopInfo pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116905 91177308-0d34-0410-b5e6-96231b3b80d8
