[PATCH] AIX os_defines.h update for math.h overloads

[David Edelsohn]

    AIX math.h provides C++ overloaded inlined math functions, which should
    not be present for G++. The definitions have been guaded by
    __COMPATMATH__, but that macro had other uses in IBM xlC++. A new
    macro has been introduced with the sole purpose of guarding the functions.
    This patch updates libstdc++ os_defines.h to define the additional macro.
    The earlier macro definition is retained to guard the functions in the
    math.h header of earlier AIX releases.

Bootstrapped on powerpc-ibm-aix7.2.3.0

    libstdc++-v3/ChangeLog:

            * config/os/aix/os_defines.h
(__LIBC_NO_CPP_MATH_OVERLOADS__): Define.

diff --git a/libstdc++-v3/config/os/aix/os_defines.h
b/libstdc++-v3/config/os/aix/os_defines.h
index 723a6533319..265e2941d1a 100644
--- a/libstdc++-v3/config/os/aix/os_defines.h
+++ b/libstdc++-v3/config/os/aix/os_defines.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-3.0-or-later WITH GCC-exception-3.1
 // Specific definitions for AIX  -*- C++ -*-

 // Copyright (C) 2000-2021 Free Software Foundation, Inc.
@@ -48,6 +49,10 @@
 #define __COMPATMATH__
 #endif

+#ifndef __LIBC_NO_CPP_MATH_OVERLOADS__
+#define __LIBC_NO_CPP_MATH_OVERLOADS__
+#endif
+
 // No support for referencing weak symbols without a definition.
 #define _GLIBCXX_USE_WEAK_REF 0