ntdll: Export _local_unwind.

dlls/kernel32/kernel32.spec

@@ -1289,6 +1289,7 @@
 @ stdcall _lclose(long)
 @ stdcall _lcreat(str long)
 @ stdcall _llseek(long long long)
+@ stdcall -arch=x86_64 -private _local_unwind(ptr ptr) ntdll._local_unwind
 @ stdcall _lopen(str long)
 @ stdcall _lread(long ptr long)
 @ stdcall _lwrite(long ptr long)

dlls/ntdll/ntdll.spec

@@ -1270,6 +1270,7 @@
 @ cdecl -private _itoa(long ptr long)
 @ cdecl -private _itow(long ptr long)
 @ cdecl -private _lfind(ptr ptr ptr long ptr)
+@ stdcall -arch=x86_64 _local_unwind(ptr ptr)
 @ cdecl -private _ltoa(long ptr long)
 @ cdecl -private _ltow(long ptr long)
 @ cdecl -private _memccpy(ptr ptr long long)

dlls/ntdll/signal_x86_64.c

@@ -3109,6 +3109,16 @@ void WINAPI RtlUnwind( void *frame, void *target_ip, EXCEPTION_RECORD *rec, void
 
 
 /*******************************************************************
+ *		_local_unwind (NTDLL.@)
+ */
+void WINAPI _local_unwind( void *frame, void *target_ip )
+{
+    CONTEXT context;
+    RtlUnwindEx( frame, target_ip, NULL, NULL, &context, NULL );
+}
+
+
+/*******************************************************************
  *		__C_specific_handler (NTDLL.@)
  */
 EXCEPTION_DISPOSITION WINAPI __C_specific_handler( EXCEPTION_RECORD *rec,