Fix unused variable in CoroFrame.cpp when building Release with GCC 10
When building with GCC 10, the following warning is reported:
/llvm-project/llvm/lib/Transforms/Coroutines/CoroFrame.cpp:1527:28: warning: unused variable ‘CS’ [-Wunused-variable] 1527 | if (CatchSwitchInst *CS =
This change adds a cast to void to avoid the warning.
Reviewed By: lxfind
Differential Revision: https://reviews.llvm.org/D94456