linux-user: Add strace support for printing arguments of fallocate()

This patch implements strace argument printing functionality for following syscall:

*fallocate - manipulate file space

int fallocate(int fd, int mode, off_t offset, off_t len)
man page: https://www.man7.org/linux/man-pages/man2/fallocate.2.html

Implementation notes:

This syscall's second argument "mode" is composed of predefined values
which represent flags that determine the type of operation that is
to be performed on the file space. For that reason, a printing
function "print_fallocate" was stated in file "strace.list". This printing
function uses an already existing function "print_flags()" to print flags of
the "mode" argument. These flags are stated inside an array "falloc_flags"
that contains values of type "struct flags". These values are instantiated
using an existing macro "FLAG_GENERIC()". Most of these flags are defined
after kernel version 3.0 which is why they are enwrapped in an #ifdef
directive.
The syscall's third ant fourth argument are of type "off_t" which can
cause variations between 32/64-bit architectures. To handle this variation,
function "target_offset64()" was copied from file "strace.c" and used in
"print_fallocate" to print "off_t" arguments for 32-bit architectures.

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200619123331.17387-7-filip.bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>