Fix issue #2010.

Alastair reported some missing cases in tp frontend action
where certain types are not adjusted.
For example, for tracepoint syscalls:sys_enter_kill,
the kernel format:
        ...
        field:int __syscall_nr; offset:8;       size:4; signed:1;
        field:pid_t pid;        offset:16;      size:8; signed:0;
        field:int sig;  offset:24;      size:8; signed:0;

The size for "pid_t pid" is 8 bytes, but the kernel pid_t
is "int", so it is needed to change its type to "s64"
to be consistent to its size.

This patch also added conversion for gid_t and uid_t as Alastair
discovered that they are also used in some tracepoints with size 8.
For type gid_t and uid_t, the corresponding kernel type is "unsigned int",
so it should be converted to "u64".
Signed-off-by: Yonghong Song <yhs@fb.com>