This patch updates fputils to the latest revision (6a47fd8358) from
the upstream repository (github.com/andysan/fputils). Most notably,
this includes changes that export a limited set of 64-bit float
manipulation and avoids a warning about unused 64-bit floats in clang.
This changeset updates the external library to git revision
52b6190b4e. This update includes changes that fix compilation errors
on old gcc versions and fixes to test a case that affect ICC.
This changeset includes libfputils from revision bbf0d61d75. This
library can be used to convert to and from 80-bit floats and query the
type of an 80-bit float, which is needed to support the x87 FPU.
