uvloop strictly needs SO_REUSEPORT

[mtelka]

uvloop expects that SO_REUSEPORT is supported everywhere. Unfortunately, there are some platforms where SO_REUSEPORT is not supported. For example illumos.

Error message:

uvloop/loop.c: In function '__pyx_gb_6uvloop_4loop_4Loop_57generator3':
uvloop/loop.c:33764:46: error: 'SO_REUSEPORT' undeclared (first use in this function); did you mean 'SO_REUSEADDR'?
33764 |             __pyx_t_5 = __Pyx_PyInt_From_int(SO_REUSEPORT); if (unlikely(!__pyx_t_5)) __PYX_ERR(0, 1778, __pyx_L32_error)
      |                                              ^~~~~~~~~~~~
      |                                              SO_REUSEADDR
uvloop/loop.c:33764:46: note: each undeclared identifier is reported only once for each function it appears in

• uvloop version: 0.17.0
• Python version: 3.9.16
• Platform: OpenIndiana/illumos
• Can you reproduce the bug with PYTHONASYNCIODEBUG in env?: N/A
• Does uvloop behave differently from vanilla asyncio? How?: N/A

Could you please detect the SO_REUSEPORT support during build and do not try to use SO_REUSEPORT if it is not available?

Thank you.