Rename class 'CFGReachabilityAnalysis' to 'CFGReverseBlockReachabilityAnalysis'.

This rename serves two purposes:

- It reflects the actual functionality of this analysis.
- We will have more than one reachability analysis.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127930 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CFGReachabilityAnalysis.cpp b/lib/Analysis/CFGReachabilityAnalysis.cpp
index 7786584..65cd089 100644
--- a/lib/Analysis/CFGReachabilityAnalysis.cpp
+++ b/lib/Analysis/CFGReachabilityAnalysis.cpp
@@ -19,10 +19,10 @@
 
 using namespace clang;
 
-CFGReachabilityAnalysis::CFGReachabilityAnalysis(const CFG &cfg)
+CFGReverseBlockReachabilityAnalysis::CFGReverseBlockReachabilityAnalysis(const CFG &cfg)
   : analyzed(cfg.getNumBlockIDs(), false) {}
 
-bool CFGReachabilityAnalysis::isReachable(const CFGBlock *Src,
+bool CFGReverseBlockReachabilityAnalysis::isReachable(const CFGBlock *Src,
                                           const CFGBlock *Dst) {
 
   const unsigned DstBlockID = Dst->getBlockID();
@@ -39,7 +39,7 @@
 
 // Maps reachability to a common node by walking the predecessors of the
 // destination node.
-void CFGReachabilityAnalysis::mapReachability(const CFGBlock *Dst) {
+void CFGReverseBlockReachabilityAnalysis::mapReachability(const CFGBlock *Dst) {
   llvm::SmallVector<const CFGBlock *, 11> worklist;
   llvm::BitVector visited(analyzed.size());