Revert "[common/core/dynarmic] Optimize page table allocations (#4219)"

src/common/virtual_buffer.cpp

@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <sys/mman.h>
+#endif
+
+#include "common/assert.h"
+#include "common/virtual_buffer.h"
+
+namespace Common {
+
+void* AllocateMemoryPages(std::size_t size) noexcept {
+#ifdef _WIN32
+    void* base = VirtualAlloc(nullptr, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+    if (base == nullptr) {
+        // Probably failing to reserve is less likely than failing to commit
+        base = VirtualAlloc(nullptr, size, MEM_COMMIT, PAGE_READWRITE);
+    }
+#else
+    void* base = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
+    if (base == MAP_FAILED)
+        base = nullptr;
+#endif
+    ASSERT(base);
+    return base;
+}
+
+void FreeMemoryPages(void* base, [[maybe_unused]] std::size_t size) noexcept {
+    if (!base)
+        return;
+#ifdef _WIN32
+    ASSERT(VirtualFree(base, 0, MEM_RELEASE));
+#else
+    ASSERT(munmap(base, size) == 0);
+#endif
+}
+
+} // namespace Common