Remove redundant checking for hasattr(self, 'activated_env') since activated_environment() function already does that. Also change activated_environment() to return a pre-split list instead of a string that caller is expected to split.

emsdk

@@ -1171,9 +1171,9 @@ class Tool:
 
   def activated_environment(self):
     if hasattr(self, 'activated_env'):
-      return self.expand_vars(self.activated_env)
+      return self.expand_vars(self.activated_env).split(';')
     else:
-      return ''
+      return []
 
   def compatible_with_this_os(self):
     if hasattr(self, 'os'):
@@ -1269,8 +1269,7 @@ class Tool:
 
   # Returns true if the system environment variables requires by this tool are currently active.
   def is_env_active(self):
-    if hasattr(self, 'activated_env'):
-      envs = self.activated_environment().split(';')
+    envs = self.activated_environment()
     for env in envs:
       (key, value) = parse_key_value(env)
       if not key in os.environ or to_unix_path(os.environ[key]) != to_unix_path(value):
@@ -1288,8 +1287,8 @@ class Tool:
     return True
 
   def win_activate_env_vars(self, permanently_activate):
-    if WINDOWS and hasattr(self, 'activated_env'):
-      envs = self.activated_environment().split(';')
+    if WINDOWS:
+      envs = self.activated_environment()
       for env in envs:
         (key, value) = parse_key_value(env)
 
@@ -1956,8 +1955,7 @@ def construct_env(tools_to_activate, permanent):
     mkdir_p(em_cache_dir)
 
   for tool in tools_to_activate:
-    if hasattr(tool, 'activated_env'):
-      envs = tool.activated_environment().split(';')
+    envs = tool.activated_environment()
     for env in envs:
       (key, value) = parse_key_value(env)
       value = to_native_path(tool.expand_vars(value))