Fix instructions for gcc,sparc,32-bit.

This fixes trac:2551.

This commit was SVN r23672.

The following Trac tickets were found above:
  Ticket 2551 --> https://svn.open-mpi.org/trac/ompi/ticket/2551

README

@@ -10,7 +10,7 @@ Copyright (c) 2004-2007 The Regents of the University of California.
                         All rights reserved.
 Copyright (c) 2006-2010 Cisco Systems, Inc.  All rights reserved.
 Copyright (c) 2006-2007 Voltaire, Inc. All rights reserved.
-Copyright (c) 2006-2008 Sun Microsystems, Inc.  All rights reserved.
+Copyright (c) 2006-2010 Oracle and/or its affiliates.  All rights reserved.
 Copyright (c) 2007      Myricom, Inc.  All rights reserved.
 Copyright (c) 2008      IBM Corporation.  All rights reserved.
 $COPYRIGHT$
@@ -226,7 +226,7 @@ Compiler Notes
   default on Sun Solaris.  The v8plus (32 bit) or v9 (64 bit)
   targets must be used to build Open MPI on Solaris.  This can be
   done by including a flag in CFLAGS, CXXFLAGS, FFLAGS, and FCFLAGS,
-  -xarch=v8plus for the Sun compilers, -mv8plus for GCC.
+  -xarch=v8plus for the Sun compilers, -mcpu=v9 for GCC.
 
 - At least some versions of the Intel 8.1 compiler seg fault while
   compiling certain Open MPI source code files.  As such, it is not