8323008: filter out harmful -std* flags added by autoconf from CXX

Reviewed-by: erikj, clanger, ihse

make/autoconf/toolchain.m4

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2024, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -389,6 +389,10 @@ AC_DEFUN_ONCE([TOOLCHAIN_POST_DETECTION],
   # This is necessary since AC_PROG_CC defaults CFLAGS to "-g -O2"
   CFLAGS="$ORG_CFLAGS"
   CXXFLAGS="$ORG_CXXFLAGS"
+
+  # filter out some unwanted additions autoconf may add to CXX; we saw this on macOS with autoconf 2.72
+  UTIL_GET_NON_MATCHING_VALUES(cxx_filtered, $CXX, -std=c++11 -std=gnu++11)
+  CXX="$cxx_filtered"
 ])
 
 # Check if a compiler is of the toolchain type we expect, and save the version

make/autoconf/util.m4

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2024, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -199,7 +199,7 @@ AC_DEFUN([UTIL_GET_NON_MATCHING_VALUES],
   if test -z "$legal_values"; then
     $1="$2"
   else
-    result=`$GREP -Fvx "$legal_values" <<< "$values_to_check" | $GREP -v '^$'`
+    result=`$GREP -Fvx -- "$legal_values" <<< "$values_to_check" | $GREP -v '^$'`
     $1=${result//$'\n'/ }
   fi
 ])
@@ -226,7 +226,7 @@ AC_DEFUN([UTIL_GET_MATCHING_VALUES],
   if test -z "$illegal_values"; then
     $1=""
   else
-    result=`$GREP -Fx "$illegal_values" <<< "$values_to_check" | $GREP -v '^$'`
+    result=`$GREP -Fx -- "$illegal_values" <<< "$values_to_check" | $GREP -v '^$'`
     $1=${result//$'\n'/ }
   fi
 ])