[Memory] Preallocate encrypted memory region

(Fixes dashboards up to 12625)

src/xenia/memory.cc

@@ -184,6 +184,12 @@ bool Memory::Initialize() {
   heaps_.physical.AllocFixed(0x1FFF0000, 0x10000, 0x10000,
                              kMemoryAllocationReserve, kMemoryProtectNoAccess);
 
+  // Pre-reserve encrypted part of memory
+  heaps_.v80000000.AllocFixed(
+      0x8C000000, 0x03FFFFFF, 0x10000,
+      kMemoryAllocationReserve | kMemoryAllocationCommit,
+      kMemoryProtectRead | kMemoryProtectWrite);
+
   // GPU writeback.
   // 0xC... is physical, 0x7F... is virtual. We may need to overlay these.
   heaps_.vC0000000.AllocFixed(