Fix GraphTraits for "const CallGraphNode *" and "const CallGraph *"

The specializations were broken. For example,

void foo(const CallGraph *G) {
  auto I = GraphTraits<const CallGraph *>::nodes_begin(G);
  auto K = I++;

  ...
}

or

void bar(const CallGraphNode *N) {
  auto I = GraphTraits<const CallGraphNode *>::nodes_begin(G);
  auto K = I++;

  ....
}

would not compile.

Patch by Speziale Ettore!

llvm-svn: 222149
diff --git a/llvm/unittests/Analysis/CMakeLists.txt b/llvm/unittests/Analysis/CMakeLists.txt
index 8454860..baf0c28 100644
--- a/llvm/unittests/Analysis/CMakeLists.txt
+++ b/llvm/unittests/Analysis/CMakeLists.txt
@@ -1,4 +1,5 @@
 set(LLVM_LINK_COMPONENTS
+  IPA
   Analysis
   AsmParser
   Core
@@ -6,6 +7,7 @@
   )
 
 add_llvm_unittest(AnalysisTests
+  CallGraphTest.cpp
   CFGTest.cpp
   LazyCallGraphTest.cpp
   ScalarEvolutionTest.cpp