This directory was copied from bash-3.2.

The header file bashansi.h has been added, copied from bash-3.2 as well.
The headers ansi_stdlib.h and xmalloc.h are from the readline lib of bash-3.2.

These files need the following autoconf macros,

AC_CONFIG_HEADERS(config.h)			For HAVE_CONFIG_H
AC_CHECK_FUNCS(getpwent getpwnam getpwuid)	For HAVE_GETPWENT, HAVE_GETPWNAM and HAVE_GETPWUID.
AC_CHECK_HEADERS(unistd.h stdlib.h string.h memory.h pwd.h strings.h)
BASH_CHECK_GETPW_FUNCS				For HAVE_GETPW_DECLS

I then added the files Makefile.am and generated Makefile.in from it.

The original README reads:

-------------------------------------------------------------------------
If you're building this separately from bash or the readline library, add
$(srcdir)/shell.c to the CSOURCES variable and shell.o to the OBJECTS
variable in Makefile.in.  (Not that this is very useful without readline
or bash.)