[ubsan] Fix looksLikeFloatCastOverflowDataV1 heuristic to work if one of the types is unknown.
[ubsan] Fix looksLikeFloatCastOverflowDataV1 heuristic to work if one of the types is unknown.

Differential revision: http://reviews.llvm.org/D13775


git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@250806 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt