Suppress useless linker warnings totally on macOS

configure.ac

@@ -427,15 +427,22 @@ AS_CASE(["$build_os"],
     # default spec.
     # Xcode linker warns for deprecated architecture and wrongly
     # installed TBD files.
-    CC_WRAPPER="" CC_NO_WRAPPER="$CC"
+    AC_MSG_CHECKING(for $CC linker warning)
+    suppress_ld_waring=no
     echo 'int main(void) {return 0;}' > conftest.c
-    AS_IF([$CC -framework Foundation -o conftest conftest.c 2>&1 |
-	   grep -e '^ld: warning: ignoring duplicate libraries:' \
-	        -e '^ld: warning: text-based stub file' >/dev/null], [
-	CC_WRAPPER=`cd -P "${tooldir}" && pwd`/darwin-cc
-	CC="$CC_WRAPPER $CC"
+    AS_IF([$CC -framework Foundation -o conftest -ggdb3 conftest.c 2>&1 |
+	   grep \
+	      -e '^ld: warning: ignoring duplicate libraries:' \
+	      -e '^ld: warning: text-based stub file' \
+	      -e '^ld: warning: -multiply_defined is obsolete' \
+	      -e "^warning: '\.debug_macinfo'" \
+	      -e '^note: while processing' \
+	   >/dev/null], [
+	suppress_ld_waring=yes
     ])
     rm -fr conftest*
+    test $suppress_ld_waring = yes && warnflags="${warnflags:+${warnflags} }-Wl,-w"
+    AC_MSG_RESULT($suppress_ld_waring)
   ])
 AS_CASE(["$target_os"],
   [wasi*], [
@@ -1768,15 +1775,16 @@ AC_CACHE_CHECK(for function name string predefined identifier,
     [AS_CASE(["$target_os"],[openbsd*],[
       rb_cv_function_name_string=__func__
      ],[
-     rb_cv_function_name_string=no
+      rb_cv_function_name_string=no
       RUBY_WERROR_FLAG([
         for func in __func__ __FUNCTION__; do
             AC_LINK_IFELSE([AC_LANG_PROGRAM([[@%:@include <stdio.h>]],
 					    [[puts($func);]])],
             [rb_cv_function_name_string=$func
             break])
         done
-      ])])]
+      ])
+    ])]
 )
 AS_IF([test "$rb_cv_function_name_string" != no], [
     AC_DEFINE_UNQUOTED(RUBY_FUNCTION_NAME_STRING, [$rb_cv_function_name_string])