Second pass idLib integration.

source/shared/idlib/parallelism/softwarecache.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <cstdint>
+
+// All four recovered template instantiations occupy exactly 128 bytes.  The
+// Xbox cache machinery is opaque until its call sites are ported, but the
+// generic declaration and storage contract are now available to PC headers.
+template<typename elementType, int cacheLines, int associativity>
+class idSoftwareCache {
+public:
+    std::uint8_t storage[128];
+};
+
+static_assert(sizeof(idSoftwareCache<int, 1, 4>) == 128,
+    "Recovered idSoftwareCache ABI changed");
+