rename floatformat_ia64_quad_{big, little} to floatformat_ieee_quad_{big, little}
I submitted a GDB patch [1] to rename floatformats_ia64_quad to
floatformats_ieee_quad to reflect the reality, and then we can
clean up the related code.
As GDB Global Maintainer Tom Tromey said [2]:
These files are maintained in gcc and then imported into the
binutils-gdb repository, so any changes to them will have to
be proposed there first.
this GCC patch is preparation for the GDB patch, no functionality
change.