Remove the "Cache full ISO in RAM" feature

It's been broken for years and nobody has even noticed enough to report
it.

Core/System.cpp

@@ -57,7 +57,6 @@
 #include "Core/Core.h"
 #include "Core/CoreTiming.h"
 #include "Core/CoreParameter.h"
-#include "Core/FileLoaders/RamCachingFileLoader.h"
 #include "Core/FileSystems/MetaFileSystem.h"
 #include "Core/Loaders.h"
 #include "Core/PSPLoaders.h"
@@ -416,18 +415,6 @@ bool PSP_InitStart(const CoreParameter &coreParam, std::string *error_string) {
 	IdentifiedFileType type = Identify_File(loadedFile, &g_CoreParameter.errorString);
 	g_CoreParameter.fileType = type;
 
-	if (g_Config.bCacheFullIsoInRam) {
-		switch (g_CoreParameter.fileType) {
-		case IdentifiedFileType::PSP_ISO:
-		case IdentifiedFileType::PSP_ISO_NP:
-			loadedFile = new RamCachingFileLoader(loadedFile);
-			break;
-		default:
-			INFO_LOG(Log::System, "RAM caching is on, but file is not an ISO, so ignoring");
-			break;
-		}
-	}
-
 	if (g_Config.bAchievementsEnable) {
 		// Need to re-identify after ResolveFileLoaderTarget - although in practice probably not,
 		// but also, re-using the identification would require some plumbing, to be done later.