+-- ToDO: add this:
+-- cml_args_regs :: [GlobalReg],
+-- It says which GlobalRegs are live for the parameters at the
+-- moment of the call. Later stages can use this to give liveness
+-- everywhere, which in turn guides register allocation.
+-- It is the companion of cml_args; cml_args says which stack words
+-- hold parameters, while cml_arg_regs says which global regs hold parameters
+