wayland-info: unbreak build on FreeBSD

Continuation of ofourdan/wayland-info!2 (closed).

program_invocation_short_name is specific to Linux (many libc except bionic) while getprogname() exists on Android, DragonFly, FreeBSD, NetBSD, OpenBSD, macOS, Solaris.

See also https://android.googlesource.com/platform/system/core/+/platform-tools-30.0.3/liblog/logger_write.cpp#112

meson.build

@@ -19,7+19,7 @@
 
 cc = meson.get_compiler('c')
 cflags = ['-Wno-unused-parameter']
 add_project_arguments(cflags, language: 'c')
 
 dep_wayland_server = dependency('wayland-server', version: '>= 1.17.0')
 dep_wayland_client = dependency('wayland-client', version: '>= 1.17.0')
@@ -30,7+30,7 @@
 if cc.has_header_symbol('errno.h', 'program_invocation_name',
                         args: '-D_GNU_SOURCE')
    # Linux (glibc, musl)
-   cflags += '-DHAVE_PROGRAM_INVOCATION_NAME'
+   config_h.set('-DHAVE_PROGRAM_INVOCATION_NAME', '1')
 elif cc.has_header_symbol('stdlib.h', 'getprogname')
    # Android, BSDs, Solaris
-   cflags += '-DHAVE_GETPROGNAME'
+   config_h.set('-DHAVE_GETPROGNAME', '1')
 endif
 configure_file(output: 'config.h', configuration: config_h)