[proc] use syscall package to call NtQueryInformationThread

I was hoping this will fix the issue below.
But there is more code that break new cgo rules.

Fixes #409 (partial)

proc/registers_windows_amd64.go

 package proc
 
-// #include "threads_windows.h"
+// #include <windows.h>
 import "C"
 import (
 	"bytes"
 	"fmt"
+	"syscall"
+	"unsafe"
 )
 
 // Regs represents CPU registers on an AMD64 processor.
@@ -121,12 +123,11 @@ func registers(thread *Thread) (Registers, error) {
 		return nil, fmt.Errorf("failed to read ThreadContext")
 	}
 
-	var threadInfo C.THREAD_BASIC_INFORMATION
-	res = C.thread_basic_information(C.HANDLE(thread.os.hThread), &threadInfo)
-	if res == C.FALSE {
+	var threadInfo _THREAD_BASIC_INFORMATION
+	status := _NtQueryInformationThread(syscall.Handle(thread.os.hThread), ThreadBasicInformation, uintptr(unsafe.Pointer(&threadInfo)), uint32(unsafe.Sizeof(threadInfo)), nil)
+	if !_NT_SUCCESS(status) {
 		return nil, fmt.Errorf("failed to get thread_basic_information")
 	}
-	tls := uintptr(threadInfo.TebBaseAddress)
 
 	regs := &Regs{
 		rax:    uint64(context.Rax),
@@ -150,7 +151,7 @@ func registers(thread *Thread) (Registers, error) {
 		cs:     uint64(context.SegCs),
 		fs:     uint64(context.SegFs),
 		gs:     uint64(context.SegGs),
-		tls:    uint64(tls),
+		tls:    uint64(threadInfo.TebBaseAddress),
 	}
 	return regs, nil
 }

proc/syscall_windows.go

+//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go syscall_windows.go
+
+package proc
+
+import (
+	"syscall"
+)
+
+type _NTSTATUS int32
+
+type _CLIENT_ID struct {
+	UniqueProcess syscall.Handle
+	UniqueThread  syscall.Handle
+}
+
+type _THREAD_BASIC_INFORMATION struct {
+	ExitStatus     _NTSTATUS
+	TebBaseAddress uintptr
+	ClientId       _CLIENT_ID
+	AffinityMask   uintptr
+	Priority       int32
+	BasePriority   int32
+}
+
+const (
+	ThreadBasicInformation = 0
+)
+
+func _NT_SUCCESS(x _NTSTATUS) bool {
+	return x >= 0
+}
+
+//sys	_NtQueryInformationThread(threadHandle syscall.Handle, infoclass int32, info uintptr, infolen uint32, retlen *uint32) (status _NTSTATUS) = ntdll.NtQueryInformationThread

proc/threads_windows.c

-#include "threads_windows.h"
-
-typedef NTSTATUS (WINAPI *pNtQIT)(HANDLE, LONG, PVOID, ULONG, PULONG);
-
-WINBOOL thread_basic_information(HANDLE h, THREAD_BASIC_INFORMATION* addr) {
-	static pNtQIT NtQueryInformationThread = NULL;
-	if(NtQueryInformationThread == NULL) {
-		NtQueryInformationThread = (pNtQIT)GetProcAddress(GetModuleHandle("ntdll.dll"), "NtQueryInformationThread");
-		if(NtQueryInformationThread == NULL) {
-			return 0;
-		}
-	}
-
-	NTSTATUS status = NtQueryInformationThread(h, ThreadBasicInformation, addr, 48, 0);
-	return NT_SUCCESS(status);
-}

proc/threads_windows.h

-#include <windows.h>
-#include <Winternl.h>
-
-typedef struct THREAD_BASIC_INFORMATION
-{
-  NTSTATUS ExitStatus;
-  PVOID TebBaseAddress;
-  CLIENT_ID ClientId;
-  ULONG_PTR AffinityMask;
-  LONG Priority;
-  LONG BasePriority;
-
-} THREAD_BASIC_INFORMATION,*PTHREAD_BASIC_INFORMATION;
-
-WINBOOL thread_basic_information(HANDLE h, PTHREAD_BASIC_INFORMATION addr);

proc/zsyscall_windows.go

+// MACHINE GENERATED BY 'go generate' COMMAND; DO NOT EDIT
+
+package proc
+
+import "unsafe"
+import "syscall"
+
+var _ unsafe.Pointer
+
+var (
+	modntdll = syscall.NewLazyDLL("ntdll.dll")
+
+	procNtQueryInformationThread = modntdll.NewProc("NtQueryInformationThread")
+)
+
+func _NtQueryInformationThread(threadHandle syscall.Handle, infoclass int32, info uintptr, infolen uint32, retlen *uint32) (status _NTSTATUS) {
+	r0, _, _ := syscall.Syscall6(procNtQueryInformationThread.Addr(), 5, uintptr(threadHandle), uintptr(infoclass), uintptr(info), uintptr(infolen), uintptr(unsafe.Pointer(retlen)), 0)
+	status = _NTSTATUS(r0)
+	return
+}