bsd_signal was removed in POSIX 2008, sysv_signal was never POSIX. Bug: 13935372 Change-Id: I7688e5cc317247ff075dcf99b598f515fb4f15c4
Also clean up <signal.h> and revert the hacks that were necessary for 64-bit in linker/debugger.cpp until now. Change-Id: I3b0554ca8a49ee1c97cda086ce2c1954ebc11892