Fixed 2 compiler warnings emitted from ./bootstrap.sh --cxx=g++

One complaining that the order in which == operators were declared was undefined, so making all four equals operations in the value_ref class depend on a single one was fragile and another that enums need to be explicitly static_casted since direct adding between two different enum types is deprecated, now the only warning is about calling free on a heap object in a yyparse function, which from a cursory glance is the compiler not realizing that it only gets freed if it isn't a heap object (#600)

src/engine/bindjam.cpp

@@ -560,7 +560,7 @@ struct jam_arg_spec_count_sum<X, A...>
 	//     = X::count + jam_arg_spec_count_sum<A...>::value;
 	enum : std::size_t
 	{
-		value = X::count + jam_arg_spec_count_sum<A...>::value
+		value = static_cast<std::size_t>(X::count) + static_cast<std::size_t>(jam_arg_spec_count_sum<A...>::value)
 	};
 };
 

src/engine/value.h

@@ -131,12 +131,15 @@ struct value_ref
 	inline bool operator==(value_ptr b) const { return val->equal_to(*b); }
 	inline bool operator==(const char * v) const
 	{
-		return (*this) == value_ref(v);
+		return val->equal_to(*value_ref(v));
 	}
-	template <typename T>
-	inline bool operator!=(T v) const
+	inline bool operator!=(value_ptr b) const
 	{
-		return !((*this) == v);
+		return !(val->equal_to(*b));
+	}
+	inline bool operator!=(const char * v) const
+	{
+		return !(val->equal_to(*value_ref(v)));
 	}
 	inline value_ptr operator->() const { return val; }
 	inline value & operator*() const { return *val; }