Backend: Create "backend" folder

similar to the "frontend" folder

src/backend/x64/block_range_information.cpp

@@ -0,0 +1,45 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2018 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#include <unordered_set>
+
+#include <boost/icl/interval_map.hpp>
+#include <boost/icl/interval_set.hpp>
+
+#include "backend/x64/block_range_information.h"
+#include "common/common_types.h"
+
+namespace Dynarmic::BackendX64 {
+
+template <typename ProgramCounterType>
+void BlockRangeInformation<ProgramCounterType>::AddRange(boost::icl::discrete_interval<ProgramCounterType> range, IR::LocationDescriptor location) {
+    block_ranges.add(std::make_pair(range, std::set<IR::LocationDescriptor>{location}));
+}
+
+template <typename ProgramCounterType>
+void BlockRangeInformation<ProgramCounterType>::ClearCache() {
+    block_ranges.clear();
+}
+
+template <typename ProgramCounterType>
+std::unordered_set<IR::LocationDescriptor> BlockRangeInformation<ProgramCounterType>::InvalidateRanges(const boost::icl::interval_set<ProgramCounterType>& ranges) {
+    std::unordered_set<IR::LocationDescriptor> erase_locations;
+    for (auto invalidate_interval : ranges) {
+        auto pair = block_ranges.equal_range(invalidate_interval);
+        for (auto it = pair.first; it != pair.second; ++it) {
+            for (const auto &descriptor : it->second) {
+                erase_locations.insert(descriptor);
+            }
+        }
+    }
+    // TODO: EFFICIENCY: Remove ranges that are to be erased.
+    return erase_locations;
+}
+
+template class BlockRangeInformation<u32>;
+template class BlockRangeInformation<u64>;
+
+} // namespace Dynarmic::BackendX64