9744 and 9745: allow taking address of static variables in CTFE

When constant-folding to produce a compile-time value, it's always been allowed to take the address of a static variable (this doesn't include thread locals). This patch allows it in CTFE as well.
Of course you cannot dereference such a pointer.

The motivation is to remove the difference between CTFE and constfolding, so that I can do a future pull request where the CTFE engine does _all_ interpreting, and optimize.c will only do optimizing.