Fix a race in the construction of future.  This fixes http://llvm.org/bugs/show_bug.cgi?id=14934.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@172456 91177308-0d34-0410-b5e6-96231b3b80d8
Make <cmath> classification macros work with integral types.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@172461 91177308-0d34-0410-b5e6-96231b3b80d8