Fix CI

test/elf/relocatable-compressed-debug-info.sh

@@ -4,6 +4,8 @@
 # OneTBB isn't tsan-clean
 nm mold | grep -q '__tsan_init' && skip
 
+echo 'int main() {}' | $GCC -o /dev/null -xc -g3 -gz - >& /dev/null || skip
+
 cat <<EOF | $GCC -c -o $t/a.o -xc - -g3 -gz
 #include <stdio.h>
 void hello() { printf("Hello world\n"); }
@@ -16,4 +18,4 @@ EOF
 
 ./mold --relocatable -o $t/c.o $t/a.o $t/b.o
 $CC -B. -o $t/exe $t/c.o
-$QEMU $t/exe
+$QEMU $t/exe | grep -q 'Hello world'