This patch seems to have broken bootstrap on AIX.  It seems to assume
methods that aren't guaranteed to be defined.

Thanks, David

libtool: compile:  /tmp/GCC/./gcc/xgcc -B/tmp/GCC/./gcc/
-B/nasfarm/edelsohn/ins
tall/GCC/powerpc-ibm-aix7.2.5.0/bin/
-B/nasfarm/edelsohn/install/GCC/powerpc-ibm
-aix7.2.5.0/lib/ -isystem
/nasfarm/edelsohn/install/GCC/powerpc-ibm-aix7.2.5.0/i
nclude -isystem
/nasfarm/edelsohn/install/GCC/powerpc-ibm-aix7.2.5.0/sys-include
 -fno-checking -DHAVE_CONFIG_H -I..
-I/nasfarm/edelsohn/src/src/libstdc++-v3/../
libiberty -I/nasfarm/edelsohn/src/src/libstdc++-v3/../include
-D_GLIBCXX_SHARED
-I/tmp/GCC/powerpc-ibm-aix7.2.5.0/libstdc++-v3/include/powerpc-ibm-aix7.2.5.0
-I
/tmp/GCC/powerpc-ibm-aix7.2.5.0/libstdc++-v3/include
-I/nasfarm/edelsohn/src/src
/libstdc++-v3/libsupc++ -I/nasfarm/edelsohn/install/include
-I/nasfarm/edelsohn/
install/include -g -O2 -DIN_GLIBCPP_V3 -Wno-error -c cp-demangle.c  -fPIC
-DPIC -o cp-demangle.o
/nasfarm/edelsohn/src/src/libstdc++-v3/libsupc++/eh_alloc.cc: In member
function 'void* {anonymous}::pool::allocate(std::size_t)':
/nasfarm/edelsohn/src/src/libstdc++-v3/libsupc++/eh_alloc.cc:239:54: error:
no matching function for call to
'__gnu_cxx::__scoped_lock::__scoped_lock(int&)'
  239 |       __gnu_cxx::__scoped_lock sentry(emergency_mutex);
      |                                                      ^
In file included from
/nasfarm/edelsohn/src/src/libstdc++-v3/libsupc++/eh_alloc.cc:37:
/tmp/GCC/powerpc-ibm-aix7.2.5.0/libstdc++-v3/include/ext/concurrence.h:240:14:
note: candidate: '__gnu_cxx::__scoped_lock::__scoped_lock(__mutex_type&)'
  240 |     explicit __scoped_lock(__mutex_type& __name) : _M_device(__name)
      |              ^~~~~~~~~~~~~
/tmp/GCC/powerpc-ibm-aix7.2.5.0/libstdc++-v3/include/ext/concurrence.h:240:42:
note:   no known conversion for argument 1 from 'int' to
'__gnu_cxx::__scoped_lock::__mutex_type&'
  240 |     explicit __scoped_lock(__mutex_type& __name) : _M_device(__name)
      |                            ~~~~~~~~~~~~~~^~~~~~
/tmp/GCC/powerpc-ibm-aix7.2.5.0/libstdc++-v3/include/ext/concurrence.h:236:5:
note: candidate: '__gnu_cxx::__scoped_lock::__scoped_lock(const
__gnu_cxx::__scoped_lock&)'
  236 |     __scoped_lock(const __scoped_lock&);
      |     ^~~~~~~~~~~~~
/tmp/GCC/powerpc-ibm-aix7.2.5.0/libstdc++-v3/include/ext/concurrence.h:236:19:
note:   no known conversion for argument 1 from 'int' to 'const
__gnu_cxx::__scoped_lock&'
  236 |     __scoped_lock(const __scoped_lock&);
      |                   ^~~~~~~~~~~~~~~~~~~~
make[5]: *** [Makefile:778: eh_alloc.lo] Error 1