meson: Fix exported functions in plugins

This adds DEF file names in meson. Without the DEF files, every
functions are exproted from plugins.

plugins/checksum/meson.build

@@ -3,4 +3,5 @@ shared_module('checksum', 'checksum.c',
   install: true,
   install_dir: plugindir,
   name_prefix: '',
+  vs_module_defs: 'checksum.def',
 )

plugins/exec/meson.build

@@ -1,5 +1,6 @@
 shared_module('exec', 'exec.c',
   dependencies: hexchat_plugin_dep,
   install: true,
-  install_dir: plugindir
+  install_dir: plugindir,
+  vs_module_defs: 'exec.def',
 )

plugins/fishlim/meson.build

@@ -19,4 +19,5 @@ shared_module('fishlim', fishlim_sources,
   install: true,
   install_dir: plugindir,
   name_prefix: '',
+  vs_module_defs: 'fishlim.def',
 )

plugins/perl/meson.build

@@ -88,4 +88,5 @@ shared_module('perl',
   install_dir: plugindir,
   install_rpath: perl_rpath,
   name_prefix: '',
+  vs_module_defs: 'perl.def',
 )

plugins/sysinfo/meson.build

@@ -57,4 +57,5 @@ shared_module('sysinfo', sysinfo_sources,
   install: true,
   install_dir: plugindir,
   name_prefix: '',
+  vs_module_defs: 'sysinfo.def',
 )

plugins/upd/meson.build

@@ -5,4 +5,5 @@ shared_module('upd', 'upd.c',
   install: true,
   install_dir: plugindir,
   name_prefix: '',
+  vs_module_defs: 'upd.def',
 )

plugins/winamp/meson.build

@@ -3,4 +3,5 @@ shared_module('winamp', 'winamp.c',
   install: true,
   install_dir: plugindir,
   name_prefix: '',
+  vs_module_defs: 'winamp.def',
 )