Kernel: Remove /proc/PID/regs

There isn't an easy way to retreive all register contents anymore,
so remove this functionality. We do have the ability to trace
processes, so it shouldn't really be needed anymore.

Kernel/FileSystem/ProcFS.cpp

@@ -110,7 +110,6 @@ enum ProcFileType {
     FI_PID_vm,
     FI_PID_vmobjects,
     FI_PID_stack,
-    FI_PID_regs,
     FI_PID_fds,
     FI_PID_unveil,
     FI_PID_exe,  // symlink
@@ -621,32 +620,6 @@ Optional<KBuffer> procfs$pid_stack(InodeIdentifier identifier)
     return process.backtrace(*handle);
 }
 
-Optional<KBuffer> procfs$pid_regs(InodeIdentifier identifier)
-{
-    auto handle = ProcessInspectionHandle::from_pid(to_pid(identifier));
-    if (!handle)
-        return {};
-    auto& process = handle->process();
-    KBufferBuilder builder;
-    process.for_each_thread([&](Thread& thread) {
-        builder.appendf("Thread %d:\n", thread.tid());
-        auto& tss = thread.tss();
-        builder.appendf("eax: %x\n", tss.eax);
-        builder.appendf("ebx: %x\n", tss.ebx);
-        builder.appendf("ecx: %x\n", tss.ecx);
-        builder.appendf("edx: %x\n", tss.edx);
-        builder.appendf("esi: %x\n", tss.esi);
-        builder.appendf("edi: %x\n", tss.edi);
-        builder.appendf("ebp: %x\n", tss.ebp);
-        builder.appendf("cr3: %x\n", tss.cr3);
-        builder.appendf("flg: %x\n", tss.eflags);
-        builder.appendf("sp:  %w:%x\n", tss.ss, tss.esp);
-        builder.appendf("pc:  %w:%x\n", tss.cs, tss.eip);
-        return IterationDecision::Continue;
-    });
-    return builder.build();
-}
-
 Optional<KBuffer> procfs$pid_exe(InodeIdentifier identifier)
 {
     auto handle = ProcessInspectionHandle::from_pid(to_pid(identifier));
@@ -1610,7 +1583,6 @@ ProcFS::ProcFS()
     m_entries[FI_PID_vm] = { "vm", FI_PID_vm, false, procfs$pid_vm };
     m_entries[FI_PID_vmobjects] = { "vmobjects", FI_PID_vmobjects, true, procfs$pid_vmobjects };
     m_entries[FI_PID_stack] = { "stack", FI_PID_stack, false, procfs$pid_stack };
-    m_entries[FI_PID_regs] = { "regs", FI_PID_regs, true, procfs$pid_regs };
     m_entries[FI_PID_fds] = { "fds", FI_PID_fds, false, procfs$pid_fds };
     m_entries[FI_PID_exe] = { "exe", FI_PID_exe, false, procfs$pid_exe };
     m_entries[FI_PID_cwd] = { "cwd", FI_PID_cwd, false, procfs$pid_cwd };