druntime's PAGESIZE

[Denis Feklushkin]

Hi!

Looks like some of these values are redundant:

src/rt/lifetime.d
31:        PAGESIZE = 4096,

src/gc/pooltable.d
181:    enum PAGESIZE = 4096;

src/gc/impl/conservative/gc.d
1133:{   PAGESIZE =    4096,

This is correct? Which ones are related to each other? Which ones 
can be freely changed so that nothing (silently) breaks?

On a small system these values ​​seems too high.