loc2c-runtime deref()

[Frank Ch. Eigler]

Hi -

The $target and $target->field extraction logic in the translator
emits code that calls the macro deref() in src/runtime/loc2c-runtime.h
to follow pointers.  This macro appears to be tuned for accessing
user-space (refers to uaccess.h's __get_user_asm).  Is there good
reason to believe it will continue to work even on kernel space
pointers?  Do those lower level macros provide sufficient detection of
null and other invalid pointer dereferencing?

- FChE