Dump how multilib iterator is invoked

Signed-off-by: Alexey Neyman <stilor@att.net>

scripts/functions

@@ -1456,6 +1456,7 @@ CT_IterateMultilibs() {
     local multi_dir multi_os_dir multi_os_dir_gcc multi_root multi_flags multi_index multi_target
     local root_suffix
     local dir_postfix
+    local v
 
     # Name used internally below
     if [ "${prefix}" = "sysroot-check" ]; then
@@ -1547,6 +1548,11 @@ CT_IterateMultilibs() {
         dir_postfix=_${multi_dir//\//_}
         dir_postfix=${dir_postfix%_.}
         CT_mkdir_pushd "${prefix}${dir_postfix}"
+        CT_DoLog DEBUG "Multilib iterator: call function '${func}' in '${prefix}${dir_postfix}'"
+        for v in multi_dir multi_os_dir multi_os_dir_gcc multi_flags multi_root multi_target multi_index; do
+            CT_DoLog DEBUG "  ${v}=${!v}"
+        done
+
         $func multi_dir="${multi_dir}"               \
               multi_os_dir="${multi_os_dir}"         \
               multi_os_dir_gcc="${multi_os_dir_gcc}" \