aml_getstack
sp = aml_getstack(root, AMLOP_ARG0 + idx);
sp = aml_getstack(root, AMLOP_LOCAL0 + idx);
fa = aml_getstack(scope, AMLOP_ARG0);
sp = aml_getstack(scope, AMLOP_ARG0+idx);
sp = aml_getstack(scope, AMLOP_LOCAL0+idx);
sp = aml_getstack(root, AMLOP_ARG0+idx);
sp = aml_getstack(root, AMLOP_LOCAL0+idx);
sp = aml_getstack(ms, AMLOP_ARG0+idx);
rv = aml_getstack(scope, opcode);
struct aml_value *aml_getstack(struct aml_scope *, int);