Add detection for zlib headers to all.sh
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 37cb93d..e7075b8 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -674,6 +674,17 @@
     msg "test: ssl-opt.sh (zlib, make)"
     if_build_succeeded tests/ssl-opt.sh
 }
+support_test_zlib_make () {
+    base=support_test_zlib_$$
+    cat <<'EOF' > ${base}.c
+#include "zlib.h"
+int main(void) { return 0; }
+EOF
+    gcc -o ${base}.exe ${base}.c -lz 2>/dev/null
+    ret=$?
+    rm -f ${base}.*
+    return $ret
+}
 
 component_test_zlib_cmake() {
     msg "build: zlib enabled, cmake"
@@ -687,6 +698,9 @@
     msg "test: ssl-opt.sh (zlib, cmake)"
     if_build_succeeded tests/ssl-opt.sh
 }
+support_test_zlib_cmake () {
+    support_test_zlib_make "$@"
+}
 
 component_test_ref_configs () {
     msg "test/build: ref-configs (ASan build)" # ~ 6 min 20s