fix(Lib/signal): not compile on Windows

Author: litlighilit

src/pylib/Lib/signal_impl/state.nim

@@ -101,17 +101,17 @@ when (NimMajor, NimMinor, NimPatch) >= (2, 1, 1):
 else:
   using destSelf: var signal_state_t
 
-proc PySignal_Fini(state: signal_state_t) =
+proc PySignal_Fini(destSelf) =
   for signum in cint(1) ..< Py_NSIG.cint:
     let fn = get_handler(signum)
     Py_atomic_store(Handlers[signum].tripped, false)
     set_handler(signum, nil)
-    if not fn.isNil and fn != state.default_handler and 
-      fn != state.ignore_handler:
+    if not fn.isNil and fn != destSelf.default_handler and 
+      fn != destSelf.ignore_handler:
         discard PyOS_setsig(signum, SIG_DFL)
   when DWin:
     if destSelf.sigint_event != Handle(0):
-      closeHandle(destSelf.sigint_event)
+      discard closeHandle(destSelf.sigint_event)
 
 proc PySignal_Fini*() = PySignal_Fini state
 

src/pylib/Python/pylifecycle/signal/c_syms.nim

@@ -10,14 +10,24 @@ const
 when defined(windows):
   import std/winlean
   export winlean
-  let SIGBREAK*{.importc, header: "<signal.h>".}: cint
+  import ./handler_types
+  template sig(sym) =
+    let sym*{.importc, header: "<signal.h>".}: cint
+
+  sig SIGBREAK
+  sig SIGABRT
+  sig SIGFPE
+  sig SIGILL
+  sig SIGINT
+  sig SIGSEGV
+  sig SIGTERM
   let
     CTRL_C_EVENT*{.importc, header: "<Windows.h>".}: cint
     CTRL_BREAK_EVENT*{.importc, header: "<Windows.h>".}: cint
-  type Sighandler = proc (a1: cint) {.cdecl.}
   let
-    SIG_DFL*{.importc, header: "<signal.h>".}: Sighandler
-    SIG_IGN*{.importc, header: "<signal.h>".}: Sighandler
+    SIG_DFL*{.importc, header: "<signal.h>".}: CSighandler
+    SIG_IGN*{.importc, header: "<signal.h>".}: CSighandler
+    SIG_ERR*{.importc, header: "<signal.h>".}: CSighandler
 else:
   import std/posix except EINTR, ERANGE
   export posix except EINTR, ERANGE

src/pylib/Python/pylifecycle/signal/chk_util.nim

@@ -1,8 +1,7 @@
 
 template ifInvalidOnVcc*(signalnum: cint, handleExc) =
   when defined(windows):
-    case signalnum
-    of SIGABRT, SIGBREAK, SIGFPE, SIGILL, SIGINT, SIGSEGV, SIGTERM: discard
+    if signalnum in {SIGABRT, SIGBREAK, SIGFPE, SIGILL, SIGINT, SIGSEGV, SIGTERM}: discard
     else:
       handleExc