test: Rename includes/pre/uv-errno.h to includes/pre/uv.h

libuv users are only supposed to directly include uv.h.  In v1.21.0, all
the uv-*.h headers were renamed to uv/*.h, which caused the unit tests
to fail with

    [123/125] Generating post/uv-errno.h
    FAILED: test/includes/post/uv-errno.h
    cd «SRCDIR»/src/neovim/build/test/includes && /usr/bin/clang -std=c99 -E -P «SRCDIR»/src/neovim/test/includes/pre/uv-errno.h -I/usr/include -I/usr/include -o «SRCDIR»/neovim/build/test/includes/post/uv-errno.h
    «SRCDIR»/src/neovim/test/includes/pre/uv-errno.h:1:10: error: 'uv-errno.h' file not found with <angled> include; use "quotes" instead
    #include <uv-errno.h>
             ^~~~~~~~~~~~
             "uv-errno.h"

The intention of the file is to extend libuv's error constants with more
values used by the unit tests.  This can just as easily be achieved
without poking into pseudo-private header files.

1 files changed, 4 insertions, 0 deletions

diff --git a/test/includes/pre/uv.h b/test/includes/pre/uv.h
new file mode 100644
index 0000000000..da7818cd07
--- /dev/null
+++ b/test/includes/pre/uv.h
@@ -0,0 +1,4 @@
+#include <uv.h>
+
+static const int kUV_ENOENT = UV_ENOENT;
+static const int kUV_EEXIST = UV_EEXIST;