qemu: Convert target_name() to TargetInfo API

Have target_name() be a target-agnostic method, dispatching
to a per-target TargetInfo singleton structure.
By default a stub singleton is used. No logical change
expected.

Inspired-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250424222112.36194-3-philmd@linaro.org>
diff --git a/meson.build b/meson.build
index 185c2fb..8ae70db 100644
--- a/meson.build
+++ b/meson.build
@@ -3795,6 +3795,7 @@
 common_ss.add(pagevary)
 specific_ss.add(files('page-target.c', 'page-vary-target.c'))
 
+common_ss.add(files('target-info.c'))
 specific_ss.add(files('target-info-stub.c'))
 
 subdir('backends')