Cannot set the return register on a call unless it is a call to an actual function

[xusheng6]

Right now we cannot set the return type of a call if it is an indirect call or a call to a pointer in a data variable. This can be set if the call it is an actual function call (using the edit function properties dialog), but there is no way to specify that info only using the type of the call. Similarly we cannot set clobbered registers for the very same reason. Luckily, we can set the type of the call, including no-return, stack adjustment, etc.