Fix Windows build with MinGW-w64's gcc-4.8.0

The use of #defines like this:

#define ERROR_IPSEC_IKE_PROCESS_ERR_ID __MSABI_LONG(13834)
#define __MSABI_LONG(x)  x ## l

in new MinGW-w64 header files trips up Errno_pm.PL, causing hundreds of
warnings like this:

Bareword found where operator expected at (eval 22) line 1, near "13834l"
        (Missing operator before l?)

and hundreds of error values to go missing from Errno.pm.

This patch, from perl #121773, fixes that.