libtool cvs: AC_PROG_NM -B when build!=host

[Kevin Ryde]

I noticed when doing a cross-compile like

 ./configure --build=alphaev5-dec-osf4.0e --host=alphaev6-dec-osf4.0f

that AC_PROG_NM only attempts to add -B or -p to
alphaev6-dec-osf4.0f-nm, not to a plain nm in $PATH.  This leads to
"command to parse nm output... failed" since -B is necessary on OSF.
I'm not sure exactly what later effects that has.

The patch below would have the loop run once for ${tmp_tool_prefix}nm
(if cross compiling) and a second time for plain nm.  I didn't
re-indent, so the diff is just the pertinent changes, but that should
be done.

        * libtool.m4 (AC_PROG_NM): When cross-compiling try -B and -p
        on plain nm as well as ${ac_tool_prefix}nm.

libtool.m4.diff
Description: Source code patch