windows: add ModuleEntry32 type and Module32{First,Next} wrappers

Reference:
https://docs.microsoft.com/en-us/windows/win32/api/tlhelp32/ns-tlhelp32-moduleentry32w
https://docs.microsoft.com/en-us/windows/win32/api/tlhelp32/nf-tlhelp32-module32firstw
https://docs.microsoft.com/en-us/windows/win32/api/tlhelp32/nf-tlhelp32-module32nextw

Change-Id: I5455cabdbaa8e7e25490f869ca349e3c6f67a0cf
Reviewed-on: https://go-review.googlesource.com/c/sys/+/369174
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Patrik Nyblom <pnyb@google.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Patrik Nyblom <pnyb@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Patrik Nyblom <pnyb@google.com>
diff --git a/windows/syscall_windows.go b/windows/syscall_windows.go
index 7702bbb..200b62a 100644
--- a/windows/syscall_windows.go
+++ b/windows/syscall_windows.go
@@ -323,6 +323,8 @@
 //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
 //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
 //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
+//sys	Module32First(snapshot Handle, moduleEntry *ModuleEntry32) (err error) = kernel32.Module32FirstW
+//sys	Module32Next(snapshot Handle, moduleEntry *ModuleEntry32) (err error) = kernel32.Module32NextW
 //sys	Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32FirstW
 //sys	Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32NextW
 //sys	Thread32First(snapshot Handle, threadEntry *ThreadEntry32) (err error)
diff --git a/windows/types_windows.go b/windows/types_windows.go
index 286dd1e..73087bf 100644
--- a/windows/types_windows.go
+++ b/windows/types_windows.go
@@ -156,6 +156,8 @@
 	MAX_PATH      = 260
 	MAX_LONG_PATH = 32768
 
+	MAX_MODULE_NAME32 = 255
+
 	MAX_COMPUTERNAME_LENGTH = 15
 
 	TIME_ZONE_ID_UNKNOWN  = 0
@@ -970,6 +972,21 @@
 	Flags          uint32
 }
 
+type ModuleEntry32 struct {
+	Size         uint32
+	ModuleID     uint32
+	ProcessID    uint32
+	GlblcntUsage uint32
+	ProccntUsage uint32
+	ModBaseAddr  uintptr
+	ModBaseSize  uint32
+	ModuleHandle Handle
+	Module       [MAX_MODULE_NAME32 + 1]uint16
+	ExePath      [MAX_PATH]uint16
+}
+
+const SizeofModuleEntry32 = unsafe.Sizeof(ModuleEntry32{})
+
 type Systemtime struct {
 	Year         uint16
 	Month        uint16
diff --git a/windows/zsyscall_windows.go b/windows/zsyscall_windows.go
index bf0dd8f..1055d47 100644
--- a/windows/zsyscall_windows.go
+++ b/windows/zsyscall_windows.go
@@ -295,6 +295,8 @@
 	procLockFileEx                                           = modkernel32.NewProc("LockFileEx")
 	procLockResource                                         = modkernel32.NewProc("LockResource")
 	procMapViewOfFile                                        = modkernel32.NewProc("MapViewOfFile")
+	procModule32FirstW                                       = modkernel32.NewProc("Module32FirstW")
+	procModule32NextW                                        = modkernel32.NewProc("Module32NextW")
 	procMoveFileExW                                          = modkernel32.NewProc("MoveFileExW")
 	procMoveFileW                                            = modkernel32.NewProc("MoveFileW")
 	procMultiByteToWideChar                                  = modkernel32.NewProc("MultiByteToWideChar")
@@ -2567,6 +2569,22 @@
 	return
 }
 
+func Module32First(snapshot Handle, moduleEntry *ModuleEntry32) (err error) {
+	r1, _, e1 := syscall.Syscall(procModule32FirstW.Addr(), 2, uintptr(snapshot), uintptr(unsafe.Pointer(moduleEntry)), 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func Module32Next(snapshot Handle, moduleEntry *ModuleEntry32) (err error) {
+	r1, _, e1 := syscall.Syscall(procModule32NextW.Addr(), 2, uintptr(snapshot), uintptr(unsafe.Pointer(moduleEntry)), 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func MoveFileEx(from *uint16, to *uint16, flags uint32) (err error) {
 	r1, _, e1 := syscall.Syscall(procMoveFileExW.Addr(), 3, uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(to)), uintptr(flags))
 	if r1 == 0 {