libuv: Explicitly enable GNU APIs on Cygwin

Backport upstream libuv commit `17ea56ee73` build: Improve build by cmake for Cygwin, 2023-01-20, v1.45.0~68) to define `_GNU_SOURCE`.
6 months ago · 93ee29964a
1 changed files with 1 additions and 0 deletions
--- a/Utilities/cmlibuv/CMakeLists.txt
+++ b/Utilities/cmlibuv/CMakeLists.txt
@ -165,6 +165,7 @@ if(CMAKE_SYSTEM_NAME MATCHES "CYGWIN" OR CMAKE_SYSTEM_NAME MATCHES "MSYS")
    include/uv/posix.h
    )
  list(APPEND uv_defines
+    _GNU_SOURCE
    )
  list(APPEND uv_sources
    src/unix/cygwin.c