[Bug lto/54206] New: build in source dir breaks lto plugin detection

["andi-gcc at firstfloor dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54206

             Bug #: 54206
           Summary: build in source dir breaks lto plugin detection
    Classification: Unclassified
           Product: gcc
           Version: 4.7.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: andi-gcc@firstfloor.org


when building inside the source dir with a plugin ld that supports plugin
this check in gcc/configure.ac fails

AC_MSG_CHECKING(linker plugin support)
gcc_cv_lto_plugin=0
if test -f liblto_plugin.la; then


Result is a compiler without ld plugin support

It works with a separate build dir

Should either handle this or error out on in tree builds