Configure only the required files on pypy.

gevent/_corecffi_build.py

@@ -227,8 +227,13 @@ _watcher_types = [
     'ev_timer',
 ]
 
-_source = """   // passed to the real C compiler
+_source = """
+// passed to the real C compiler
 #define LIBEV_EMBED 1
+#ifdef _WIN32
+#define EV_STANDALONE 1
+#endif
+
 #include "libev_vfd.h"
 #include "libev.h"
 

setup.py

@@ -340,7 +340,8 @@ elif PYPY:
     # XXX ugly - need to find a better way
     system('cp -r libev gevent/libev')
     system('touch gevent/libev/__init__.py')
-    system('cd gevent/libev && ./configure > configure_output.txt')
+    if sys.platform != 'win32':
+        system('cd gevent/libev && ./configure > configure_output.txt')
     # XXX: Note that we're NOT adding the distutils extension module, but
     # doing so compiles the module already: import gevent._corecffi_build
     # imports gevent, which imports the hub, which imports the core,