stubs: Move qemu_fd_register stub to util/main-loop.c

The linker of MinGW sometimes runs into the following problem:

libqemuutil.a(util_main-loop.c.obj): In function `qemu_fd_register':
/builds/huth/qemu/build/../util/main-loop.c:331: multiple definition of
 `qemu_fd_register'
libqemuutil.a(stubs_fd-register.c.obj):/builds/huth/qemu/stubs/fd-register.c:5:
 first defined here
collect2: error: ld returned 1 exit status
/builds/huth/qemu/rules.mak:88: recipe for target 'tests/test-timed-average.exe'
 failed

qemu_fd_register() is defined in util/main-loop.c for WIN32, so let's simply
move the stub also there in the #else part of the corresponding #ifndef
to fix this problem.

Message-Id: <20200903054503.425435-1-thuth@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

stubs/fd-register.c

@@ -1,6 +0,0 @@
-#include "qemu/osdep.h"
-#include "qemu/main-loop.h"
-
-void qemu_fd_register(int fd)
-{
-}

stubs/meson.build

@@ -9,7 +9,6 @@ stub_ss.add(files('cpu-get-clock.c'))
 stub_ss.add(files('cpu-get-icount.c'))
 stub_ss.add(files('dump.c'))
 stub_ss.add(files('error-printf.c'))
-stub_ss.add(files('fd-register.c'))
 stub_ss.add(files('fdset.c'))
 stub_ss.add(files('fw_cfg.c'))
 stub_ss.add(files('gdbstub.c'))

util/main-loop.c

@@ -179,6 +179,10 @@ static int max_priority;
 static int glib_pollfds_idx;
 static int glib_n_poll_fds;
 
+void qemu_fd_register(int fd)
+{
+}
+
 static void glib_pollfds_fill(int64_t *cur_timeout)
 {
     GMainContext *context = g_main_context_default();