Allow to link against libexecinfo on linux systems
Allow to link against libexecinfo on linux systems

Some C-libraries like the Musl libc don't provide execinfo themself so
it is required to use a third party library to use execinfo there.

ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,csound/csound,csound/csound,ketchupok/csound,csound/csound,csound/csound,csound/csound,csound/csound,csound/csound,ketchupok/csound,ketchupok/csound,csound/csound