Verify function prototypes before trying to optimize functions. We also
need TargetData, just return false if we don't have it.

Update testcases accordingly.

Fixes PR6807.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101011 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed