fix(Lib/signal): lock was nil on Windows

Author: litlighilit

src/pylib/Lib/os_impl/util/mywinlean.nim

@@ -61,7 +61,8 @@ typedef union _LARGE_INTEGER {
 
   WCHAR* = uint16
 
-  WIN32_FIND_DATAW*{.importc, header: "<minwinbase.h>".} = object
+  WIN32_FIND_DATAW*{.importc, header: "<Windows.h>" # MinGW error if using <minwinbase.h>
+  .} = object
     dwFileAttributes*: DWORD
     ftCreationTime*: FILETIME
     ftLastAccessTime*: FILETIME

src/pylib/Lib/signal_impl/state.nim

@@ -83,6 +83,7 @@ proc set_handler*(i: cint, fn: PySigHandler) =
 when compileOption("threads"):
   import  std/locks
   var lock: Lock
+  lock.initLock()
   template withLock(body) =
     lock.withLock body
 else:
@@ -117,3 +118,4 @@ proc PySignal_Fini*() = PySignal_Fini state
 
 proc `=destroy`(destSelf) =
   PySignal_Fini(destSelf)
+  deinitLock lock