meson: switch function tests from compilation to linking

Some tests for glibc functions cause compilation to emit warnings but
still succeed even if the function is not there.  Therefore, change
from cc.compiles to cc.links.

Reported-by: Richard Zak <richard.j.zak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

meson.build

@@ -1340,10 +1340,10 @@ config_host_data.set('HAVE_STRUCT_STAT_ST_ATIM',
                      cc.has_member('struct stat', 'st_atim',
                                    prefix: '#include <sys/stat.h>'))
 
-config_host_data.set('CONFIG_EVENTFD', cc.compiles('''
+config_host_data.set('CONFIG_EVENTFD', cc.links('''
   #include <sys/eventfd.h>
   int main(void) { return eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); }'''))
-config_host_data.set('CONFIG_FDATASYNC', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_FDATASYNC', cc.links(gnu_source_prefix + '''
   #include <unistd.h>
   int main(void) {
   #if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0
@@ -1352,22 +1352,22 @@ config_host_data.set('CONFIG_FDATASYNC', cc.compiles(gnu_source_prefix + '''
   #error Not supported
   #endif
   }'''))
-config_host_data.set('CONFIG_MADVISE', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_MADVISE', cc.links(gnu_source_prefix + '''
   #include <sys/types.h>
   #include <sys/mman.h>
   #include <stddef.h>
   int main(void) { return madvise(NULL, 0, MADV_DONTNEED); }'''))
-config_host_data.set('CONFIG_MEMFD', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_MEMFD', cc.links(gnu_source_prefix + '''
   #include <sys/mman.h>
   int main(void) { return memfd_create("foo", MFD_ALLOW_SEALING); }'''))
-config_host_data.set('CONFIG_OPEN_BY_HANDLE', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_OPEN_BY_HANDLE', cc.links(gnu_source_prefix + '''
   #include <fcntl.h>
   #if !defined(AT_EMPTY_PATH)
   # error missing definition
   #else
   int main(void) { struct file_handle fh; return open_by_handle_at(0, &fh, 0); }
   #endif'''))
-config_host_data.set('CONFIG_PIPE2', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_PIPE2', cc.links(gnu_source_prefix + '''
   #include <unistd.h>
   #include <fcntl.h>
 
@@ -1376,16 +1376,16 @@ config_host_data.set('CONFIG_PIPE2', cc.compiles(gnu_source_prefix + '''
       int pipefd[2];
       return pipe2(pipefd, O_CLOEXEC);
   }'''))
-config_host_data.set('CONFIG_POSIX_MADVISE', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_POSIX_MADVISE', cc.links(gnu_source_prefix + '''
   #include <sys/mman.h>
   #include <stddef.h>
   int main(void) { return posix_madvise(NULL, 0, POSIX_MADV_DONTNEED); }'''))
-config_host_data.set('CONFIG_SIGNALFD', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_SIGNALFD', cc.links(gnu_source_prefix + '''
   #include <unistd.h>
   #include <sys/syscall.h>
   #include <signal.h>
   int main(void) { return syscall(SYS_signalfd, -1, NULL, _NSIG / 8); }'''))
-config_host_data.set('CONFIG_SPLICE', cc.compiles(gnu_source_prefix + '''
+config_host_data.set('CONFIG_SPLICE', cc.links(gnu_source_prefix + '''
   #include <unistd.h>
   #include <fcntl.h>
   #include <limits.h>