pgraph: Add missing `PandaNodePipelineReader::get_into_collide_mask()`

panda/src/pgraph/pandaNode.I

@@ -1476,6 +1476,14 @@ has_tag(const std::string &key) const {
   return _cdata->_tag_data.find(key) >= 0;
 }
 
+/**
+ * Returns the "into" collide mask for this node.
+ */
+INLINE CollideMask PandaNodePipelineReader::
+get_into_collide_mask() const {
+  return _cdata->_into_collide_mask;
+}
+
 /**
  * Returns the union of all into_collide_mask() values set at CollisionNodes
  * at this level and below.

panda/src/pgraph/pandaNode.h

@@ -880,6 +880,7 @@ public:
   INLINE std::string get_tag(const std::string &key) const;
   INLINE bool has_tag(const std::string &key) const;
 
+  INLINE CollideMask get_into_collide_mask() const;
   INLINE CollideMask get_net_collide_mask() const;
   INLINE const RenderAttrib *get_off_clip_planes() const;
   INLINE const BoundingVolume *get_bounds() const;