Define _DEFAULT_SOURCE to suppress a warning in glibc >= 2.20
Define _DEFAULT_SOURCE to suppress a warning in glibc >= 2.20

glibc 2.20 deprecated _BSD_SOURCE and _SVID_SOURCE in favor of
_DEFAULT_SOURCE. glibc will issue a warning if _BSD_SOURCE is defined,
but _DEFAULT_SOURCE is not. We need to set both to maintain
compatibility with other versions of libc.

hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,CoryMcCartan/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel