patch 8.1.1182: some function prototypes are outdated

Problem:    Some function prototypes are outdated.
Solution:   Update function prototypes. (Ken Takata, closes #4267)
diff --git a/src/terminal.c b/src/terminal.c
index c0777b2..7dd0387 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -5663,6 +5663,19 @@
 /**************************************
  * 2. MS-Windows implementation.
  */
+#ifdef PROTO
+typedef int COORD;
+typedef int DWORD;
+typedef int HANDLE;
+typedef int *DWORD_PTR;
+typedef int HPCON;
+typedef int HRESULT;
+typedef int LPPROC_THREAD_ATTRIBUTE_LIST;
+typedef int PSIZE_T;
+typedef int PVOID;
+typedef int SIZE_T;
+typedef int WINAPI;
+#endif
 
 HRESULT (WINAPI *pCreatePseudoConsole)(COORD, HANDLE, HANDLE, DWORD, HPCON*);
 HRESULT (WINAPI *pResizePseudoConsole)(HPCON, COORD);