[gcc r13-7223] install.texi: Document --enable-decimal-float for AArch64

[gcc r13-7223] install.texi: Document --enable-decimal-float for AArch64

[Christophe Lyon]

https://gcc.gnu.org/g:5ff54e49a666aab237393a92c7bd357f5a912229

commit r13-7223-g5ff54e49a666aab237393a92c7bd357f5a912229
Author: Christophe Lyon <christophe.lyon@arm.com>
Date:   Mon Apr 17 19:23:54 2023 +0200

    install.texi: Document --enable-decimal-float for AArch64
    
    When I committed the patches to enable support for DFP on AArch64, I
    forgot to update the installation documentation.
    
    This patch adds AArch64 as needed (same as i386/x86_64).
    
    2023-04-17  Christophe Lyon  <christophe.lyon@arm.com>
    
            gcc/
            * doc/install.texi (enable-decimal-float): Add AArch64.
    
    (cherry picked from commit cbddd574a78529b9176eb28253c20a335daefbb4)

Diff:
---
 gcc/doc/install.texi | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 15aef1394f4..b13bc122513 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -2178,13 +2178,14 @@ forward to maintain the port.
 @itemx --enable-decimal-float=dpd
 @itemx --disable-decimal-float
 Enable (or disable) support for the C decimal floating point extension
-that is in the IEEE 754-2008 standard.  This is enabled by default only
-on PowerPC, i386, and x86_64 GNU/Linux systems.  Other systems may also
-support it, but require the user to specifically enable it.  You can
-optionally control which decimal floating point format is used (either
-@samp{bid} or @samp{dpd}).  The @samp{bid} (binary integer decimal)
-format is default on i386 and x86_64 systems, and the @samp{dpd}
-(densely packed decimal) format is default on PowerPC systems.
+that is in the IEEE 754-2008 standard.  This is enabled by default
+only on AArch64, PowerPC, i386, and x86_64 GNU/Linux systems.  Other
+systems may also support it, but require the user to specifically
+enable it.  You can optionally control which decimal floating point
+format is used (either @samp{bid} or @samp{dpd}).  The @samp{bid}
+(binary integer decimal) format is default on AArch64, i386 and x86_64
+systems, and the @samp{dpd} (densely packed decimal) format is default
+on PowerPC systems.
 
 @item --enable-fixed-point
 @itemx --disable-fixed-point