Fix some bogus testsuite failures for avr.

Fix some bogus testsuite failures for avr.

gcc/testsuite/

        * c-c++-common/Wduplicated-cond-3.c (fn10): Use smaller
        const literal.
        * c-c++-common/builtin-arith-overflow-2.c: Skip for avr.
        * c-c++-common/pr68833-1.c: Require int32plus.
        * gcc.dg/ipa/pr63551.c: Likewise.
        * gcc.dg/ipa/pr63595.c: Require ptr32plus.
        * gcc.dg/ipa/pr64041.c: Require int32plus.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@238294 138bc75d-0d04-0410-961f-82ee72b054a4