https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121159
--- Comment #28 from Rainer Orth <ro at gcc dot gnu.org> ---
Btw., I noticed that the test is already skipped in plugins.exp on arm/thumb1:
# Skip tail call tests on targets that do not have sibcall_epilogue.
if {[regexp ".*must_tail_call_plugin.c" $plugin_src]
&& [istarget arm*-*-*]
&& [check_effective_target_arm_thumb1]} then {
continue
}
