llvm-isel-fuzzer: Use the right REQUIRES line for r315599

I'd mixed up ENABLE_SHARED and BUILD_SHARED_LIBS before, so these
tests were being disabled in too many places.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315646 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed