add hidden version of &errno accessor function

[musl] / configure

diff --git a/configure b/configure
index 6e489a1..de2add1 100755 (executable)
--- a/configure
+++ b/configure
@@ -507,7 +507,7 @@ tryflag CFLAGS_AUTO -Werror=pointer-arith
 # parameter to stop printing warnings about LDFLAGS passed during
 # compiling stage and CFLAGS passed during linking stage.
 #
-tryflag CFLAGS_AUTO -Qunused-arguments
+test "$cc_family" = clang && tryflag CFLAGS_AUTO -Qunused-arguments
 
 if test "x$warnings" = xyes ; then
 tryflag CFLAGS_AUTO -Wall