windows: check util.mainfrozen() instead of ad-hoc checks everywhere

mercurial/help.py

@@ -31,7 +31,7 b' def loaddoc(topic):'
     """Return a delayed loader for help/topic.txt."""
 
     def loader():
-        if hasattr(sys, 'frozen'):
+        if util.mainfrozen():
             module = sys.executable
         else:
             module = __file__

mercurial/hook.py

@@ -28,7 +28,7 b' def _pythonhook(ui, repo, name, hname, f'
                                'a module)') % (hname, funcname))
         modname = funcname[:d]
         oldpaths = sys.path
-        if hasattr(sys, "frozen"):
+        if util.mainfrozen():
             # binary installs require sys.path manipulation
             modpath, modfile = os.path.split(modname)
             if modpath and modfile:

mercurial/templater.py

@@ -341,7 +341,7 b' def templatepath(name=None):'
     normpaths = []
 
     # executable version (py2exe) doesn't support __file__
-    if hasattr(sys, 'frozen'):
+    if util.mainfrozen():
         module = sys.executable
     else:
         module = __file__