The variable "Latch" is only used in an assert, which makes builds that use...

The variable "Latch" is only used in an assert, which makes builds that use "-DNDEBUG" fail with unused variable messages.

Summary: Move the logic into the assert itself.

Subscribers: hiraditya, sanjoy, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64654

llvm-svn: 365943