[x/6][PATCH] Portability tweaks for LTO tests.

[Dave Korn <dave dot korn dot cygwin at gmail dot com>]

    Hi list,

  This is out of the main series, because it's a couple of tweaks to the LTO
tests in HJ's branch; included here for reference, since I've been running
tests with it folded in.  I notice it's slightly outdated here, as upstream HJ
has already added gcc_ld_flag (and gcc_gas_flag, in fact) to the ld/12365 test
in lto.exp, so that bit won't apply cleanly, but the second change in that
hunk (adding a '_?' prefix to the regex) is still needed.  FYI, YMMV.

ld/testsuite/ChangeLog:

2011-02-20  Dave Korn  <...

	* ld-plugin/lto-10r.d: Allow optional underscore prefixes when
	checking for known symbol name.
	* ld-plugin/lto-3r.d: Likewise.
	* ld-plugin/lto-5r.d: Likewise.
	* ld-plugin/lto-6.c: Handle non-standard etext name on Windows.
	* ld-plugin/lto.exp: Add $gcc_ld_flag carrying -B option to ld under
	test when invoking $CC directly rather than via lib support routines.


    cheers,
      DaveK