Add _FEATURE_SIE to Visual Studio project preprocessor defines.

This is purely cosmetic. Hercules uses makefiles to build with and thus does not use Visual Studio's preprocessor defines. It only uses the values specifically defined in its makefile. This change is only so Visual Studio's "Intellisense" feature doesn't visually "disable" (gray out) active code sections in its editor because it thinks it's inactive code, and is thus a purely cosmetic change.
Fix SEGFAULT caused by recent performance patch.(*)

(*) REGS structure cache-line align / page-align change.

(You missed a few spots Mark!)  :)