[cmake] refactor: Use CPM over submodules (#143)

Transfers the majority of submodules and large externals to CPM, using source archives rather than full Git clones. Not only does this save massive amounts of clone and configure time, but dependencies are grabbed on-demand rather than being required by default. Additionally, CPM will (generally) automatically search for system dependencies, though certain dependencies have options to control this.

Testing shows gains ranging from 5x to 10x in terms of overall clone/configure time.

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/143
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>

src/dynarmic/tests/fp/mantissa_util_tests.cpp

@@ -0,0 +1,66 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2018 MerryMage
+ * SPDX-License-Identifier: 0BSD
+ */
+
+#include <tuple>
+#include <vector>
+
+#include <catch2/catch_test_macros.hpp>
+#include "dynarmic/common/common_types.h"
+
+#include "../rand_int.h"
+#include "dynarmic/common/fp/mantissa_util.h"
+#include "dynarmic/common/safe_ops.h"
+
+using namespace Dynarmic;
+using namespace Dynarmic::FP;
+
+TEST_CASE("ResidualErrorOnRightShift", "[fp]") {
+    const std::vector<std::tuple<u32, int, ResidualError>> test_cases{
+        {0x00000001, 1, ResidualError::Half},
+        {0x00000002, 1, ResidualError::Zero},
+        {0x00000001, 2, ResidualError::LessThanHalf},
+        {0x00000002, 2, ResidualError::Half},
+        {0x00000003, 2, ResidualError::GreaterThanHalf},
+        {0x00000004, 2, ResidualError::Zero},
+        {0x00000005, 2, ResidualError::LessThanHalf},
+        {0x00000006, 2, ResidualError::Half},
+        {0x00000007, 2, ResidualError::GreaterThanHalf},
+    };
+
+    for (auto [mantissa, shift, expected_result] : test_cases) {
+        const ResidualError result = ResidualErrorOnRightShift(mantissa, shift);
+        REQUIRE(result == expected_result);
+    }
+}
+
+TEST_CASE("ResidualErrorOnRightShift Randomized", "[fp]") {
+    for (size_t test = 0; test < 100000; test++) {
+        const u64 mantissa = mcl::bit::sign_extend<32, u64>(RandInt<u32>(0, 0xFFFFFFFF));
+        const int shift = RandInt<int>(-60, 60);
+
+        const ResidualError result = ResidualErrorOnRightShift(mantissa, shift);
+
+        const u64 calculated_error = Safe::ArithmeticShiftRightDouble(mantissa, u64(0), shift);
+        const ResidualError expected_result = [&] {
+            constexpr u64 half_error = 0x8000'0000'0000'0000ull;
+            if (calculated_error == 0) {
+                return ResidualError::Zero;
+            }
+            if (calculated_error < half_error) {
+                return ResidualError::LessThanHalf;
+            }
+            if (calculated_error == half_error) {
+                return ResidualError::Half;
+            }
+            return ResidualError::GreaterThanHalf;
+        }();
+
+        INFO(std::hex << "mantissa " << mantissa << " shift " << shift << " calculated_error " << calculated_error);
+        REQUIRE(result == expected_result);
+    }
+}