builtins.def (BUILT_IN_CABS, [...]): New builtins representing ISO C99's cabs, cabsf and cabsl.
* builtins.def (BUILT_IN_CABS, BUILT_IN_CABSF, BUILT_IN_CABSL):
New builtins representing ISO C99's cabs, cabsf and cabsl.
* builtins.c (expand_builtin_fabs): New function.
(expand_builtin_cabs): New function.
(expand_builtin): Expand BUILT_IN_FABS{,F,L} and BUILT_IN_CABS{,F,L}
using expand_builtin_fabs and expand_builtin_cabs respectively.
* doc/extend.texi: Document new cabs, cabsf and cabsl builtins.