Auto merge of #1473 - Wind-River:master, r=gnzlbg

Some update for vxWorks

This is to address issues:
rust-lang#1469 and rust-random/getrandom#86 (comment)

What have been changed in this PR:

 1. adding randBytes(), randABytes(), randUBytes(), randSecure() and taskDelay()
 2. change armv7-wrs-vxworks to armv7-wrs-vxworks-eabihf
 3. code cleanup