acconfig.h: List _GLIBCPP_USE_THREADS.

2000-10-24  Phil Edwards  <pme@sources.redhat.com>

        * acconfig.h:  List _GLIBCPP_USE_THREADS.
        * acinclude.m4:  General formatting cleanup (tabs/spaces), typo
          correction, etc.  Add comments about following *real* changes
          where they are used.
          (GLIBCPP_ENABLE_C_MBCHAR):  New test...
          (GLIBCPP_CHECK_WCHAR_T_SUPPORT):  ...results used here.
          (GLIBCPP_ENABLE_CSTDIO):  Define need_wlibio iff wide characters
          are requested.
          (GLIBCPP_ENABLE_THREADS):  If threads are used, define new
          macro _GLIBCPP_USE_THREADS in c++config.h.
          (GLIBCPP_ENABLE_SHADOW):  For C_INCLUDE_DIR, change () to {} as
          this is used in both makefiles and shell scripts (mkcheck).
        * configure.in:  Call GLIBCPP_ENABLE_C_MBCHAR.

        * libio/_G_config.h:  Wrap _IO_MTSAFE_IO in _GLIBCPP_USE_THREADS.
        * config/c_io_libio.h:  In nonthreaded case, typedef __c_lock to
          something harmless, like int.

        * config/os/aix/bits/os_defines.h:  Guard with _GLIBCPP_OS_DEFINES,
          add comment/instructions.
        * config/os/bsd/bits/os_defines.h:  Ditto.
        * config/os/generic/bits/os_defines.h:  Ditto.
        * config/os/gnu-linux/bits/os_defines.h:  Ditto.
        * config/os/irix/bits/os_defines.h:  Ditto.
        * config/os/newlib/bits/os_defines.h:  Ditto.
        * config/os/solaris/solaris2.5/bits/os_defines.h:  Ditto.
        * config/os/solaris/solaris2.6/bits/os_defines.h:  Ditto.

        * mkcheck.in:  Limit the available heap size for testsuite
          binaries, initially at 2MB.

From-SVN: r37050