[patch testsuite]: Fix regressions in gcc-c-torture's builtin-tests using LTO on mingw-targets

[Kai Tietz]

Hello,

this patch fixes 23 regressions about LTO and double-defined symbols for
memcpy/memset.  Issue is that for mingw-targets the C-runtime functions aren't
weak and not necessarily overridable.

ChangeLog

2013-03-08  Kai Tietz  <kti...@redhat.com>

        * gcc.c-torture/execute/builtins/builtins.exp: Add for mingw
        targets linker option --allow-multiple-definition.

Ok for apply ?

Regards,
Kai

Index: builtins.exp
===================================================================
--- builtins.exp        (Revision 196543)
+++ builtins.exp        (Arbeitskopie)
@@ -42,6 +42,7 @@ if [istarget "powerpc-*-darwin*"] {
    lappend additional_flags "-Wl,-multiply_defined,suppress"
 }
 if { [istarget *-*-eabi*]
+     || [istarget *-*-mingw*]
      || [istarget *-*-elf] } {
    lappend additional_flags "-Wl,--allow-multiple-definition"
 }