Build failure with xlc 13.1.3, designated initializer bug
AIX Version: 7100-03-05-1524
XLC Version: 13.01.0003.0000
Samba Version: 4.3.5

[1927/3435] Compiling source4/torture/smb2/lock.c                               
"../source4/torture/smb2/lock.c", line 2897.35: 1506-196 (S) Initialization
between types "unsigned long long" and "struct smb2_handle" is not allowed.
"../source4/torture/smb2/lock.c", line 2919.35: 1506-196 (S) Initialization
between types "unsigned long long" and "struct smb2_handle" is not allowed.
Waf: Leaving directory `/usr/src/samba-4.3.5/bin'
Build failed:  -> task failed (err #1):     
        {task: cc lock.c -> lock_1.o}                      
make: 1254-004 The error code from the last command is 1.


Stop.

This is a bug in xlc, a PMR has been opened to get it fixed.
Adding curly brackets around the problematic fields fixes the bug (see patch).

Is this too simple a fix? I considered using #ifs but 5 lines for a syntactic
problem seemed too gross for me. Eg (not tested):

#define IBMC_COMPAT_INITIALIZERS 1313
[...]
#if defined(__IMBC__) && __IBMC__ <= IBMC_COMPAT_INITIALIZERS 
    .context = {.pid = pid},
#else 
    .context.pid = pid,
#endif