Add cmake configuration files

src/closures.c

@@ -127,6 +127,7 @@ ffi_closure_free (void *ptr)
 /* Windows systems may have Data Execution Protection (DEP) enabled, 
    which requires the use of VirtualMalloc/VirtualFree to alloc/free
    executable memory. */
+#  undef FFI_MMAP_EXEC_WRIT
 #  define FFI_MMAP_EXEC_WRIT 1
 # endif
 #endif

src/dlmalloc.c

@@ -451,6 +451,7 @@ DEFAULT_MMAP_THRESHOLD       default: 256K
 #ifdef WIN32
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+#undef HAVE_MMAP
 #define HAVE_MMAP 1
 #define HAVE_MORECORE 0
 #define LACKS_UNISTD_H