[Bug libstdc++/86553] libstdc++-v3 build failure on AIX 5.3

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86553

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
As I suspected, something is doing:

#define fabsl(X) fabs((double) (X))
#define acosl(X) acos((double) (X))
etc.

This would probably be solved by any fix for PR 79700, which would have to add
this to <cmath>:

#undef fabsl

But I'm not sure when PR 79700 will get fixed.