Add a test case for LICM when promoting locals that may be read after the...

Add a test case for LICM when promoting locals that may be read after the throw within the loop. NFCI.

Summary: Add a test case for LICM when promoting locals that may be read after the throw within the loop.

Reviewers: eli.friedman, hfinkel, sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28822

llvm-svn: 292261