meson: depend on epoll-shim for BSDs

src/util-sources.c:29:10: fatal error: 'sys/epoll.h' file not found
 #include <sys/epoll.h>
          ^~~~~~~~~~~~~

ld: error: undefined symbol: epoll_ctl
>>> referenced by util-sources.c:76 (src/util-sources.c:76)
>>>               libutil.a.p/util-sources.c.o:(source_remove) in archive src/libutil.a
>>> referenced by util-sources.c:200 (src/util-sources.c:200)
>>>               libutil.a.p/util-sources.c.o:(sink_add_source) in archive src/libutil.a

ld: error: undefined symbol: epoll_create1
>>> referenced by util-sources.c:152 (src/util-sources.c:152)
>>>               libutil.a.p/util-sources.c.o:(sink_new) in archive src/libutil.a

ld: error: undefined symbol: epoll_wait
>>> referenced by util-sources.c:169 (src/util-sources.c:169)
>>>               libutil.a.p/util-sources.c.o:(sink_dispatch) in archive src/libutil.a

meson.build

@@ -78,6 +78,7 @@ if cc.has_function('memfd_create', prefix: '#define _GNU_SOURCE\n#include <sys/m
 endif
 
 dep_math = cc.find_library('m', required: false)
+dep_epoll = dependency('epoll-shim', required: false)
 dep_libxkbcommon = dependency('xkbcommon', required: false)
 config_h.set10('HAVE_LIBXKBCOMMON', dep_libxkbcommon.found())
 dep_libevdev = dependency('libevdev', required: false)

src/meson.build

@@ -11,7 +11,7 @@ src_libutil = files(
 lib_util = static_library('util',
     src_libutil,
     include_directories: [inc_builddir],
-    dependencies: [dep_math],
+    dependencies: [dep_math, dep_epoll],
 )
 
 dep_libutil = declare_dependency(link_with: lib_util)

test/meson.build

@@ -24,7 +24,7 @@ test('unit-tests-utils',
                src_libutil,
                include_directories: [inc_src, inc_builddir],
                c_args: ['-D_enable_tests_'],
-               dependencies: [dep_unittest, dep_math]))
+               dependencies: [dep_unittest, dep_math, dep_epoll]))
 
 test('unit-tests-ei',
     executable('unit-tests-ei',