Storable: Need more stack reserve on cygwin also

Same stack quirks as on MSWin32.
cygwin64 cannot even do 32, try 40.

Author: rurban

dist/Storable/Storable.xs

@@ -374,7 +374,10 @@ typedef struct stcxt {
 /* JSON::XS has 512 */
 /* sizes computed with stacksize. use some reserve for the croak cleanup. */
 #include "stacksize.h"
-#ifdef WIN32
+/* esp. cygwin64 cannot 32, cygwin32 can */
+#if defined(__CYGWIN__) && (PTRSIZE == 8)
+# define STACK_RESERVE 128
+#elif defined(WIN32)
 # define STACK_RESERVE 32
 #else
 /* 8 should be enough, but some systems, esp. 32bit, need more */