r283051 added some functions to cmath (in namespace std) that have the
same name as functions in math.h (in the global namespace). Clang's
limited support for `-fdelayed-template-parsing` chokes on this. Rename
the ones in `cmath` and their uses in `complex` and the test.
rdar://problem/32848355
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@307357 91177308-0d34-0410-b5e6-96231b3b80d8
This fails with gcc because __builtin_isnan and friends, which
libcpp_isnan and friends call, are not themselves constexpr-evaluatable.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@287041 91177308-0d34-0410-b5e6-96231b3b80d8
