lib/int_math: Some versions of GCC don't provide __builtin_isfinite. Support them.
lib/int_math: Some versions of GCC don't provide __builtin_isfinite. Support
them.

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@144810 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