Revert r193022 and r193048.  They broke the ubsan test suite.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193057 91177308-0d34-0410-b5e6-96231b3b80d8
Implement function type checker for the undefined behavior sanitizer.

This uses function prefix data to store function type information at the
function pointer.

Differential Revision: http://llvm-reviews.chandlerc.com/D1338

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193058 91177308-0d34-0410-b5e6-96231b3b80d8