a large memory buffer on Windows

fil_extend_space_to_desired_size(), os_file_set_size(): Use calloc()
for memory allocation, and handle failures. Properly check the return
status of posix_fallocate(), and pass the correct arguments to
posix_fallocate().

On Windows, instead of extending the file by at most 1 megabyte at a time,
write a zero-filled page at the end of the file.
According to the Microsoft blog post
https://blogs.msdn.microsoft.com/oldnewthing/20110922-00/?p=9573
this will physically extend the file by writing zero bytes.
(InnoDB never uses DeviceIoControl() to set the file sparse.)

I tested that the file extension works properly with a multi-file
system tablespace, both with --innodb-use-fallocate and
--skip-innodb-use-fallocate (the default):

./mtr \
--mysqld=--innodb-use-fallocate \
--mysqld=--innodb-autoextend-increment=1 \
--mysqld=--innodb-data-file-path='ibdata1:5M;ibdata2:5M:autoextend' \
--parallel=auto --force --retry=0 --suite=innodb &

ls -lsh mysql-test/var/*/mysqld.1/data/ibdata2
(several samples while running the test)