mt_resource_rb_node_t: add ==, != operators

Problem: `mt_resource_rb_node_t` needs `==` and `!=` operators to
simplify and improve equality testing for planner updates, assignment,
and copy construction.

Add the operators.

Author: milroy

resource/planner/c++/mintime_resource_tree.cpp

@@ -207,6 +207,17 @@ bool mt_resource_rb_node_t::operator< (const mt_resource_rb_node_t &other) const
     return this->remaining < other.remaining;
 }
 
+bool mt_resource_rb_node_t::operator== (const mt_resource_rb_node_t &other) const
+{
+    return this->remaining == other.remaining;
+}
+
+bool mt_resource_rb_node_t::operator!= (const mt_resource_rb_node_t &other) const
+{
+    return !operator == (other);
+}
+
+
 
 /*******************************************************************************
  *                                                                             *

resource/planner/c++/mintime_resource_tree.hpp

@@ -24,6 +24,8 @@ struct mt_resource_rb_node_t
     int64_t subtree_min;
     int64_t remaining;
     bool operator< (const mt_resource_rb_node_t &other) const;
+    bool operator== (const mt_resource_rb_node_t &other) const;
+    bool operator!= (const mt_resource_rb_node_t &other) const;
 };
 
 template <class mt_resource_rb_node_t, class NodeTraits>