[x32] PATCH: Document --enable-ia32 and --enable-x32

[H.J. Lu]

Hi,

I checked this patch into x32 branch.

H.J.
commit d41e1fd1c4d8114532152647e5fc5b6bc3bce5dd
Author: H.J. Lu <hjl.to...@gmail.com>
Date:   Tue Jun 7 11:39:27 2011 -0700

    Document --enable-ia32 and --enable-x32.

diff --git a/gcc/ChangeLog.x32 b/gcc/ChangeLog.x32
index 06d931a..3ce5fa1 100644
--- a/gcc/ChangeLog.x32
+++ b/gcc/ChangeLog.x32
@@ -1,3 +1,7 @@
+2011-06-07  H.J. Lu  <hongjiu...@intel.com>
+
+       * doc/install.texi: Document --enable-ia32 and --enable-x32.
+
 2011-06-06  H.J. Lu  <hongjiu...@intel.com>
 
        * config.gcc: Replace i386/t-linuxx32 with i386/t-linux-x32.
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 7ebcd92..f63094c 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -1155,6 +1155,16 @@ assumptions made by the configure test are incorrect.
 Specify that the target does not support TLS.
 This is an alias for @option{--enable-tls=no}.
 
+@item --enable-ia32
+This option enables ia32 library support for multiple ABIs.  By
+default, ia32 library support is enabled.  It is only supported for
+x86-64.
+
+@item --enable-x32
+This option enables x32 library support for multiple ABIs. By
+default, x32 library support is disabled.  It is only supported for
+x86-64.
+
 @item --with-cpu=@var{cpu}
 @itemx --with-cpu-32=@var{cpu}
 @itemx --with-cpu-64=@var{cpu}