[dynarmic] add current code page cache (#3459)

should make JIT translation a bit faster - especially for non-fastmem
test if thumb still werks

previously:
we read 32-bits one by one, and do translation **for each u32 we read**

now:
one big read of 4096 bytes (aligned of course), only 1 VAddr translation

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3459
Reviewed-by: DraVee <dravee@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

src/dynarmic/src/dynarmic/interface/code_page.h

@@ -0,0 +1,17 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+
+namespace Dynarmic {
+
+/// @brief Smallest valid page (may change for Apple?)
+constexpr inline uint64_t CODE_PAGE_SIZE = 4096;
+struct CodePage {
+    uint32_t inst[CODE_PAGE_SIZE / sizeof(uint32_t)];
+};
+
+}