Bug 1720935: Move state_dir creation comment r=ahal

I'm guessing that the code moved to the bootstrap command but the
associated comment was forgotten and left abandoned, which is very sad.

Differential Revision: https://phabricator.services.mozilla.com/D120098

build/mach_bootstrap.py

@@ -225,14 +225,6 @@ def bootstrap(topsrcdir):
         site_paths = set(site.getsitepackages() + [site.getusersitepackages()])
         sys.path = [path for path in sys.path if path not in site_paths]
 
-    # Global build system and mach state is stored in a central directory. By
-    # default, this is ~/.mozbuild. However, it can be defined via an
-    # environment variable. We detect first run (by lack of this directory
-    # existing) and notify the user that it will be created. The logic for
-    # creation is much simpler for the "advanced" environment variable use
-    # case. For default behavior, we educate users and give them an opportunity
-    # to react. We always exit after creating the directory because users don't
-    # like surprises.
     sys.path[0:0] = mach_sys_path(topsrcdir)
     import mach.base
     import mach.main

python/mozboot/mozboot/bootstrap.py

@@ -227,6 +227,13 @@ class Bootstrapper(object):
         self.instance = cls(**args)
 
     def create_state_dir(self):
+        # Global build system and mach state is stored in a central directory. By
+        # default, this is ~/.mozbuild. However, it can be defined via an
+        # environment variable. We detect first run (by lack of this directory
+        # existing) and notify the user that it will be created. The logic for
+        # creation is much simpler for the "advanced" environment variable use
+        # case. For default behavior, we educate users and give them an opportunity
+        # to react.
         state_dir = get_state_dir()
 
         if not os.path.exists(state_dir):