Building tls1.6.7 on a Solaris 11.2 machine(yes, old) with developerstudio12.5 compiler gives warnings:

"tls.c", line 1528: warning: argument #4 is incompatible with prototype:
        prototype: pointer to const unsigned char : line 1021
        argument : pointer to char
(and 6 more copies of that warning for lines 1529 to 1534)

This ticket is mostly for documenting purposes.
On Solaris 11.3 with same compiler version no warnings show up.