SaveState: Only rehash functions in code a load changed

Every load hashed all known functions again, for the replacement hooks:
2.4-6 ms, about half the load. Functions in module code the load left as
it was keep their hash, so only the rest is hashed now (0.5-1 ms). The
code is compared on every load for this, not only with a JIT.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Core/HLE/sceKernelModule.h

@@ -231,6 +231,9 @@ KernelObject *__KernelModuleObject();
 void __KernelModuleDoState(PointerWrap &p);
 // The code of the loaded modules, as (address, size).
 std::vector<std::pair<u32, u32>> __KernelModuleCodeRanges();
+// For the next savestate load: code it leaves as it was, as (address, size). Its functions aren't
+// hashed again.
+void __KernelModuleSetUnchangedCodeOnLoad(std::vector<std::pair<u32, u32>> unchanged);
 void __KernelModuleShutdown();
 
 class MIPSState;