Doc update to mention MPFR (Re: [RFC][00/19] Target FP: Precise target floating-point emulation)

[Eli Zaretskii]

> Date: Mon, 20 Nov 2017 14:44:12 +0100 (CET)
> From: "Ulrich Weigand" <uweigand@de.ibm.com>
> Cc: brobecker@adacore.com, gdb-patches@sourceware.org
> 
> --- binutils-gdb.orig/gdb/NEWS
> +++ binutils-gdb/gdb/NEWS
> @@ -3,6 +3,10 @@
>  
>  *** Changes since GDB 8.0
>  
> +* GDB now uses the GNU MPFR library, if available, to emulate target
> +  floating-point arithmetic during expression evaluation when the target
> +  uses different floating-point formats than the host.
> +

This part is OK.

> +   GDB uses GNU MPFR, a library for multiple-precision floating-point
> +computation with correct rounding, to emulate target floating-point
> +arithmetic during expression evaluation when the target uses different
> +floating-point formats than the host.  MPFR will be linked in if it is
> +available at build time.  At least version 3.1 of GNU MPFR is required.
> +If GNU MPFR it is not available, GDB will fall back to using host
> +floating-point arithmetic.  The latest version of GNU MPFR should be
> +available from `http://www.mpfr.org´.
                                      ^
Some non-ASCII character sneaked in here.

> +`--with-mpfr'
> +     Build GDB with the GNU MPFR library.  (Done by default if
> +     GNU MPFR is installed and found at configure time.)  This library
> +     is used to emulate target floating-point arithmetic during expression
> +     evaluation when the target uses different floating-point formats than
> +     the host. At least version 3.1 of GNU MPFR is required.  If GNU MPFR

I would drop the reference to minimum supported MPFR version here: it
tends to become outdated as time goes by, and I believe the configure
script includes the necessary tests for what we need from MPFR, and
will reject versions that don't fit the bill.

(It is okay to have the version mentioned in NEWS, as that is a
one-time announcement.)

Also, please make sure there are 2 spaces between sentences.

> +@item MPFR
> +@anchor{MPFR}
> +@value{GDBN} can use the GNU MPFR multiple-precision floating-point
> +library.  This library may be included with your operating system
> +distribution; if it is not, you can get the latest version from
> +@url{http://www.mpfr.org}.  At least version 3.1 of GNU MPFR is
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Same here.

> +formats than the host.  If GNU MPFR it is not available, GDB will
                                                            ^^^
@value{GDBN}

The changes are okay with those gotchas fixed.

Thanks.