win32: register SEH in startup code (i386 only)

Needed to handle signal() etc. with msvcrt

win32/lib/wincrt1.c

@@ -10,6 +10,7 @@ void _controlfp(unsigned a, unsigned b);
 
 int _winstart(void)
 {
+    __TRY__
     char *szCmd;
     STARTUPINFO startinfo;
     int fShow;