gh-115806: Make configure output more readable (#115807)

- make sure LDLIBRARY and HOSTRUNNER checks don't overlap
- make the ipv6 library check less subtle

configure.ac

@@ -1415,11 +1415,13 @@ else # shared is disabled
       ;;
   esac
 fi
+AC_MSG_RESULT([$LDLIBRARY])
 
 if test "$cross_compiling" = yes; then
   RUNSHARED=
 fi
 
+AC_MSG_CHECKING([HOSTRUNNER])
 AC_ARG_VAR([HOSTRUNNER], [Program to run CPython for the host platform])
 if test -z "$HOSTRUNNER"
 then
@@ -1465,7 +1467,6 @@ then
   )
 fi
 AC_SUBST([HOSTRUNNER])
-AC_MSG_CHECKING([HOSTRUNNER])
 AC_MSG_RESULT([$HOSTRUNNER])
 
 if test -n "$HOSTRUNNER"; then
@@ -1473,8 +1474,6 @@ if test -n "$HOSTRUNNER"; then
   PYTHON_FOR_BUILD="_PYTHON_HOSTRUNNER='$HOSTRUNNER' $PYTHON_FOR_BUILD"
 fi
 
-AC_MSG_RESULT([$LDLIBRARY])
-
 # LIBRARY_DEPS, LINK_PYTHON_OBJS and LINK_PYTHON_DEPS variable
 AS_CASE([$ac_sys_system/$ac_sys_emscripten_target],
   [Emscripten/browser*], [LIBRARY_DEPS='$(PY3LIBRARY) $(WASM_STDLIB) python.html python.worker.js'],
@@ -4522,12 +4521,13 @@ yes
 fi
 
 if test "$ipv6" = "yes" -a "$ipv6lib" != "none"; then
+    AC_MSG_CHECKING([ipv6 library])
 	if test -d $ipv6libdir -a -f $ipv6libdir/lib$ipv6lib.a; then
 		LIBS="-L$ipv6libdir -l$ipv6lib $LIBS"
-		AC_MSG_NOTICE([using lib$ipv6lib])
+		AC_MSG_RESULT([lib$ipv6lib])
 	else
     AS_VAR_IF([ipv6trylibc], [yes], [
-      AC_MSG_NOTICE([using libc])
+      AC_MSG_RESULT([libc])
     ], [
       AC_MSG_ERROR([m4_normalize([
         No $ipv6lib library found; cannot continue.