* Makefile.am (CFILES): Add cxxfilt.c.
(cxxfilt_SOURCES): Now just cxxfilt.c $(BULIBS).
(cxxfilt_LDADD): Delete.
Remove all references to underscore.c.
Regen dependencies.
* configure.in: Define TARGET_PREPENDS_UNDERSCORE in
config.h from $UNDERSCORE, rather than AC_SUBSTing it.
* binutils/cxxfilt.c: Moved here from gcc/cp, minor
adjustments to fit into binutils framework.
* configure, config.in, Makefile.in, doc/Makefile.in: Regenerate.
gcc/cp:
* Make-lang.in: Remove all references to the demangler.
* cxxfilt.c: Moved to binutils.
