Allow actions to load their module implementations on-demand.

By only registering the action, we skip the processing that would been necessary to load and evaluate the module scripts. This will allow us to improve overall performance while also scaling up the number of supported actions. To force loading of the entire module (to override specific calls, for instance), call require().

.hgsubstate

@@ -1 +1 @@
-3935627f6ef6f848afd1ac3b22cc1eaa7b34a582 modules/xcode
+e68bbf571323ec91c409ee86f057c2b380aa35d9 modules/xcode

src/_manifest.lua

@@ -85,4 +85,8 @@
 		"actions/clean/_clean.lua",
 
 		"_premake_init.lua",
+
+		-- Built-in action modules. The action is registered, but the actual
+		-- implementation is not loaded unless the action is used.
+		"modules/xcode/_action.lua",
 	}

src/base/action.lua

@@ -197,6 +197,11 @@
 		if act then
 			_OS = act.os or _OS
 		end
+
+		-- Some are implemented in standalone modules
+		if act and act.module then
+			require(act.module)
+		end
 	end