[analyzer] Rename generateNode -> addTransition in CheckerContext

Also document addTransition methods.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143059 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/ChrootChecker.cpp b/lib/StaticAnalyzer/Checkers/ChrootChecker.cpp
index 769a93e..2f3ff26 100644
--- a/lib/StaticAnalyzer/Checkers/ChrootChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/ChrootChecker.cpp
@@ -94,7 +94,7 @@
   // Once encouter a chroot(), set the enum value ROOT_CHANGED directly in 
   // the GDM.
   state = Mgr.addGDM(state, ChrootChecker::getTag(), (void*) ROOT_CHANGED);
-  C.generateNode(state);
+  C.addTransition(state);
 }
 
 void ChrootChecker::Chdir(CheckerContext &C, const CallExpr *CE) const {
@@ -120,7 +120,7 @@
     }
   }
 
-  C.generateNode(state);
+  C.addTransition(state);
 }
 
 // Check the jail state before any function call except chroot and chdir().
@@ -146,7 +146,7 @@
   void *const* k = state->FindGDM(ChrootChecker::getTag());
   if (k)
     if (isRootChanged((intptr_t) *k))
-      if (ExplodedNode *N = C.generateNode()) {
+      if (ExplodedNode *N = C.addTransition()) {
         if (!BT_BreakJail)
           BT_BreakJail.reset(new BuiltinBug("Break out of jail",
                                         "No call of chdir(\"/\") immediately "