Modify Solaris Studio Complier notes about using xarch

This commit was SVN r25770.

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) 2006-2011 Mellanox Technologies. All rights reserved.
-Copyright (c) 2006-2010 Oracle and/or its affiliates.  All rights reserved.
+Copyright (c) 2006-2012 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 (c) 2010      Oak Ridge National Labs.  All rights reserved.
@@ -224,11 +224,11 @@ Compiler Notes
   example, such configurations may require additional compiler /
   linker flags to make Open MPI build properly.
 
-- Open MPI does not support the Sparc v8 CPU target, which is the
+- Open MPI does not support the Sparc v8 CPU target.  However,
-  default on Sun Solaris.  The v8plus (32 bit) or v9 (64 bit)
+  as of Solaris Studio 12.1,  and later compilers, one should not 
-  targets must be used to build Open MPI on Solaris.  This can be
+  specify -xarch=v8plus or -xarch=v9.  The use of the options
-  done by including a flag in CFLAGS, CXXFLAGS, FFLAGS, and FCFLAGS,
+  -m32 and -m64 for producing 32 and 64 bit targets, respectively,
-  -xarch=v8plus for the Sun compilers, -mcpu=v9 for GCC.
+  are now preferred by the Solaris Studio compilers.
 
 - 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