[msan] Make msan-handle-icmp-exact=0 by default.

50% slowdown on one of the specs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173678 91177308-0d34-0410-b5e6-96231b3b80d8
Revert r173678.

Broken tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173679 91177308-0d34-0410-b5e6-96231b3b80d8