HostAllocator: Make Create64BitAllocator() return a unique_ptr

Communicates the ownership intent in the interface.

Also removes the prototype for CreateBasicAllocator, as it isn't
implemented anywhere.

External/FEXCore/Source/Utils/Allocator.cpp

@@ -74,7 +74,7 @@ namespace FEXCore::Allocator {
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   void SetupHooks() {
-    Alloc64.reset(Alloc::OSAllocator::Create64BitAllocator());
+    Alloc64 = Alloc::OSAllocator::Create64BitAllocator();
     __mmap_hook   = FEX_mmap;
     __munmap_hook = FEX_munmap;
     FEXCore::Allocator::mmap = FEX_mmap;

External/FEXCore/Source/Utils/Allocator/64BitAllocator.cpp

@@ -709,7 +709,7 @@ OSAllocator_64Bit::~OSAllocator_64Bit() {
   }
 }
 
-Alloc::HostAllocator *Create64BitAllocator() {
-  return new OSAllocator_64Bit{};
+std::unique_ptr<Alloc::HostAllocator> Create64BitAllocator() {
+  return std::make_unique<OSAllocator_64Bit>();
 }
 }

External/FEXCore/Source/Utils/Allocator/HostAllocator.h

@@ -1,6 +1,8 @@
 #pragma once
+
 #include <cstddef>
 #include <cstdint>
+#include <memory>
 #include <sys/types.h>
 
 constexpr static uint64_t PAGE_SIZE = 4096;
@@ -36,10 +38,8 @@ static inline uint64_t AlignUp(uint64_t value, uint64_t size) {
       virtual void *memalign(size_t alignment, size_t size) = 0;
       virtual void free(void *ptr) = 0;
   };
-
-  GlobalAllocator *CreateBasicAllocator(HostAllocator *Alloc);
 }
 
 namespace Alloc::OSAllocator {
-Alloc::HostAllocator *Create64BitAllocator();
+std::unique_ptr<Alloc::HostAllocator> Create64BitAllocator();
 }