text/template: reduce maxExecDepth for gccgo further

text/template: reduce maxExecDepth for gccgo further

    We already lowered the limit of recursive template invocations from
    100,000 to 10,000, but the tests still fail occasionally on
    x86_64-pc-linux-gnu when using GNU ld (so that split stacks are not
    fully functional).  Reduce the limit further, to 1000, enough so that
    the test passes consistently.

    Permitting 1000 recursive template invocations still seems capacious
    enough for real world use.

    Reviewed-on: https://go-review.googlesource.com/25590

From-SVN: r239261