Introduce and test NodeProperties::CollectControlProjections.

src/compiler/node-properties.h

Index: src/compiler/node-properties.h
diff --git a/src/compiler/node-properties.h b/src/compiler/node-properties.h
index b40faf39d407916c48501dc0d5d7dfe3ad92ed99..a13eea3a02d550840d58f05249aaee8bc98fc48a 100644
--- a/src/compiler/node-properties.h
+++ b/src/compiler/node-properties.h
@@ -90,6 +90,12 @@ class NodeProperties FINAL {
 
   static Node* FindProjection(Node* node, size_t projection_index);
 
+  // Collect the branch-related projections from a node, such as IfTrue,
+  // IfFalse, IfValue and IfDefault.
+  //  - Branch: [ IfTrue, IfFalse ]
+  //  - Switch: [ IfValue, ..., IfDefault ]
+  static void CollectControlProjections(Node* node, Node** proj, size_t count);
+
 
   // ---------------------------------------------------------------------------
   // Type Bounds.