[ValueTracking] remove overzealous assert

The test is derived from a failing fuzz test:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5008

Credit to @rksimon for pointing out the problem.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322016 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed