- implement flag variables with the VM's sbit and lbit instructions.

- synthesize PField entries from the flag list for AActor. This intentionally excludes the bounce flags for now.
- allow deprecated flags that do not call the deprecated flag handler.
- disallow constructs like (a = b) = c by not allowing an address request on an assignment operation.
- restrict modify/assign on boolean variables to the bit operators. Everything else needs to promote the result to an integer to make sense so it should be disallowed.

src/scripting/thingdef.h

@@ -24,6 +24,7 @@ struct FFlagDef
 	const char *name;
 	int structoffset;
 	int fieldsize;
+	bool deprecated;
 };
 
 FFlagDef *FindFlag (const PClass *type, const char *part1, const char *part2, bool strict = false);