FYI: Fix boilerplate code with "set -x"

[Ralf Wildenhues]

* Ralf Wildenhues wrote on Tue, Sep 06, 2005 at 06:06:05PM CEST:
> 
> OK to apply the patch below to HEAD and the attached backport to
> branch-1-5?

FYI: both patches applied (71 hours, 50 mins ;-)

Cheers,
Ralf

>         * libltdl/m4/libtool.m4 (_LT_COMPILER_BOILERPLATE)
>         (_LT_LINKER_BOILERPLATE, _LT_COMPILER_OPTION, _LT_LINKER_OPTION)
>         (_LT_COMPILER_C_O): When comparing expected and actual compiler/
>         linker output for warnings, weed out both empty lines as well as
>         lines starting with possibly indented `+', to allow for shell
>         debugging with `set -x'.
>         Check the weeded instead of unweeded contents for emptiness.