tests: correctly handle the skippability of wxwidgets framework

Back when we originally added this "if found, do fundamental logic" code
in commit 24aa7f3, conditionally
performing the test logic was the state of the art. Later that year, we
implemented the MESON_SKIP_TEST protocol for actually marking skipped
tests as skipped, rather than silently doing nothing. We should use this
so that people know when the test was skipped. :)

test cases/frameworks/9 wxwidgets/meson.build

@@ -5,17 +5,18 @@ project('wxwidgets test', 'cpp', default_options : ['cpp_std=c++11'])
 wxd = dependency('wxwidgets', version : '>=5', required : false)
 wxd = dependency('wxwidgets', version : '>=3.0.0', required : false)
 
-if wxd.found()
-  wp = executable('wxprog', 'wxprog.cpp', dependencies : wxd)
+if not wxd.found()
+  error('MESON_SKIP_TEST: wxwidgets dependency not found')
+endif
 
-  test('wxtest', wp)
+wp = executable('wxprog', 'wxprog.cpp', dependencies : wxd)
 
-  # WxWidgets framework is available, we can use required here
-  wx_stc = dependency('wxwidgets', version : '>=3.0.0', modules : ['std', 'stc'])
-  stc_exe = executable('wxstc', 'wxstc.cpp', dependencies : wx_stc)
-  test('wxstctest', stc_exe)
+test('wxtest', wp)
 
-  # Check we can apply a version constraint
-  dependency('wxwidgets', version: '>=@0@'.format(wxd.version()))
+# WxWidgets framework is available, we can use required here
+wx_stc = dependency('wxwidgets', version : '>=3.0.0', modules : ['std', 'stc'])
+stc_exe = executable('wxstc', 'wxstc.cpp', dependencies : wx_stc)
+test('wxstctest', stc_exe)
 
-endif
+# Check we can apply a version constraint
+dependency('wxwidgets', version: '>=@0@'.format(wxd.version()))