Merge bitcoin/bitcoin#26952: build: Avoid `BOOST_NO_CXX98_FUNCTION_BASE` macro redefinition

d4c59da8d6 build: Avoid `BOOST_NO_CXX98_FUNCTION_BASE` macro redefinition (Hennadii Stepanov)

Pull request description:

  With GCC 12 and Boost 1.81 (from depends) having multiple warnings:
  ```
  In file included from /home/hebasto/bitcoin/depends/x86_64-pc-linux-gnu/include/boost/config.hpp:48:
  /home/hebasto/bitcoin/depends/x86_64-pc-linux-gnu/include/boost/config/stdlib/libstdcpp3.hpp:397:9: warning: 'BOOST_NO_CXX98_FUNCTION_BASE' macro redefined [-Wmacro-redefined]
  #define BOOST_NO_CXX98_FUNCTION_BASE
          ^
  <command line>:8:9: note: previous definition is here
  #define BOOST_NO_CXX98_FUNCTION_BASE 1
          ^
  1 warning generated.
  ```

  This PR fixes those warnings.

  Defining of the `BOOST_NO_CXX98_FUNCTION_BASE` macro was introduced in https://github.com/bitcoin/bitcoin/pull/25436, but since https://github.com/boostorg/config/pull/430, it is required to check it before adding.

ACKs for top commit:
  fanquake:
    ACK d4c59da8d6 - it works now.

Tree-SHA512: 53b9ddcf8dad729638ed41251e30c80f2d7d1ae3ffe47466865834f1f10184fe0881abeb339b3e46c270c3eb11fb63d19ab12cc9461bf5c2be12b4763c1b1c34

configure.ac

@@ -1467,9 +1467,11 @@ if test "$use_boost" = "yes"; then
   BOOST_CPPFLAGS="$BOOST_CPPFLAGS -DBOOST_MULTI_INDEX_DISABLE_SERIALIZATION"
 
   dnl Prevent use of std::unary_function, which was removed in C++17,
-  dnl and will generate warnings with newer compilers.
-  dnl See: https://github.com/boostorg/container_hash/issues/22.
-  BOOST_CPPFLAGS="$BOOST_CPPFLAGS -DBOOST_NO_CXX98_FUNCTION_BASE"
+  dnl and will generate warnings with newer compilers for Boost
+  dnl older than 1.80.
+  dnl See: https://github.com/boostorg/config/pull/430.
+  AX_CHECK_PREPROC_FLAG([-DBOOST_NO_CXX98_FUNCTION_BASE], [BOOST_CPPFLAGS="$BOOST_CPPFLAGS -DBOOST_NO_CXX98_FUNCTION_BASE"], [], [$CXXFLAG_WERROR],
+                        [AC_LANG_PROGRAM([[#include <boost/config.hpp>]])])
 
   if test "$enable_debug" = "yes" || test "$enable_fuzz" = "yes"; then
     BOOST_CPPFLAGS="$BOOST_CPPFLAGS -DBOOST_MULTI_INDEX_ENABLE_SAFE_MODE"