Reenabled addreadlookup() and addwritelookup() in mem/mem.c, fixes performance of the emulator.

src/mem/mem.c

@@ -549,8 +549,6 @@ addreadlookup(uint32_t virt, uint32_t phys)
     uint32_t a;
 #endif
 
-    return;
-
     if (virt == 0xffffffff) return;
 
     if (readlookup2[virt>>12] != (uintptr_t) LOOKUP_INV) return;
@@ -586,8 +584,6 @@ addwritelookup(uint32_t virt, uint32_t phys)
     uint32_t a;
 #endif
 
-    return;
-
     if (virt == 0xffffffff) return;
 
     if (page_lookup[virt >> 12]) return;