[PATCH 0/3 V2] Honor --disable-decimal-float in PowerPC libgcc _Float128

[Michael Meissner]

I have broken the patches I submitted on Friday February 26th into 3 patches.
These patches allow us to build the libgcc library on PowerPC for VSX systems
and optionally enable/disable the Decimal support.  If Decimal support is
disabled, then the Float128 <-> Decimal conversions are not built.

I have done bootstraps on a little endian power9 system with each of the long
double variants (128-bit IBM, 128-bit IEEE, 64-bit) enabled, and there were no
regressions in each of the builds with the previous version.

In addition, I have built 2 cross compilers from my x86_64 system to little
endian PowerPC Linux.  One build enabled decimal support and one disabled the
decimal support.  On the build that disabled decimal support, I verified that
the _Float128 <-> Decimal conversions were not built.

Can I check these patches into the master branch for GCC 11?

The 3 patches are:

   #1: Fix __sprintfkf prototype to match between .h and .c files;
   #2: Eliminate including stdio.h in _sprintfkf.c; (and)
   #3: Disable building _Float128 <-> Decimal conversions if
       --disable-decimal-float.

-- 
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.ibm.com, phone: +1 (978) 899-4797