Add lrint to the list of math builtins. It never sets errno so we can mark it as readnone.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@188065 91177308-0d34-0410-b5e6-96231b3b80d8
Fixup for r188058: assume hasAsanZeroBaseShadow() is false if ASan is not needed

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@188068 91177308-0d34-0410-b5e6-96231b3b80d8