make nodeids precalculated, there is no sane reason to commpute lazyly

_pytest/main.py

@@ -300,7 +300,7 @@ class Session(nodes.FSCollector):
     def __init__(self, config):
         nodes.FSCollector.__init__(
             self, config.rootdir, parent=None,
-            config=config, session=self)
+            config=config, session=self, nodeid="")
         self.testsfailed = 0
         self.testscollected = 0
         self.shouldstop = False
@@ -311,9 +311,6 @@ class Session(nodes.FSCollector):
 
         self.config.pluginmanager.register(self, name="session")
 
-    def _makeid(self):
-        return ""
-
     @hookimpl(tryfirst=True)
     def pytest_collectstart(self):
         if self.shouldfail: