While running configure I got the following, hopefully it will get to the right person. It was compiling on a SunFire V490.
checking signal.h usability... no
checking signal.h presence... yes
configure: WARNING: signal.h: present but cannot be compiled
configure: WARNING: signal.h: check for missing prerequisite headers?
configure: WARNING: signal.h: see the Autoconf documentation
configure: WARNING: signal.h: section "Present But Cannot Be Compiled"
configure: WARNING: signal.h: proceeding with the preprocessor's result
configure: WARNING: signal.h: in the future, the compiler will take precedence
configure: WARNING: ## ------------------------------ ##
configure: WARNING: ## Report this to the vlc lists. ##
configure: WARNING: ## ------------------------------ ##