* modules/floorf-ieee: New file.
* m4/floorf.m4 (gl_FUNC_FLOORF): If gl_FUNC_FLOORF_IEEE is also used,
test whether floorf works according to ISO C 99 with IEC 60559.
* m4/floorf-ieee.m4: New file.
* modules/floorf-ieee-tests: New file.
* tests/test-floorf-ieee.c: New file, based on tests/test-floorf1.c.
* tests/test-floorf1.c (main): Remove signbit tests.
* modules/floorf-tests (Depends-on): Remove 'signbit'.
* doc/posix-functions/floorf.texi: Mention the new module.