kernel/process: move current process to kernel instance

Two functional change:
QueryProcessMemory uses the process passed from handle instead current_process
Thread::Stop() uses TLS from owner_process instead of current_process

src/core/file_sys/archive_savedata.cpp

@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include <utility>
+#include "core/core.h"
 #include "core/file_sys/archive_savedata.h"
 #include "core/hle/kernel/process.h"
 
@@ -16,16 +17,19 @@ ArchiveFactory_SaveData::ArchiveFactory_SaveData(
     : sd_savedata_source(std::move(sd_savedata)) {}
 
 ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_SaveData::Open(const Path& path) {
-    return sd_savedata_source->Open(Kernel::g_current_process->codeset->program_id);
+    return sd_savedata_source->Open(
+        Core::System::GetInstance().Kernel().GetCurrentProcess()->codeset->program_id);
 }
 
 ResultCode ArchiveFactory_SaveData::Format(const Path& path,
                                            const FileSys::ArchiveFormatInfo& format_info) {
-    return sd_savedata_source->Format(Kernel::g_current_process->codeset->program_id, format_info);
+    return sd_savedata_source->Format(
+        Core::System::GetInstance().Kernel().GetCurrentProcess()->codeset->program_id, format_info);
 }
 
 ResultVal<ArchiveFormatInfo> ArchiveFactory_SaveData::GetFormatInfo(const Path& path) const {
-    return sd_savedata_source->GetFormatInfo(Kernel::g_current_process->codeset->program_id);
+    return sd_savedata_source->GetFormatInfo(
+        Core::System::GetInstance().Kernel().GetCurrentProcess()->codeset->program_id);
 }
 
 } // namespace FileSys