libc: add posix_fallocate()

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
test: run test{,_glibc} adjacent

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
stdlib: Fix fndecl of mkostemp, mkostemp64

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
libc/{arm, i386}/Makefile.arch: Don't build 64-bit code if LFS is disabled

Fixes the following compilation error:

_lfs_64.h: # error Do not include this header in files not built when LFS is disabled

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>