Enable soft-fp on i586

This is a porting of the patches in meta-zephyr-sdk to gcc-8.2.0

We merge:
	recipes-devtools/gcc/files/libgcc-t-zephyr.patch
	recipes-devtools/gcc/files/config-x86-multi-gcc.patch
	recipes-devtools/gcc/files/x86-multilib.patch
	recipes-devtools/gcc/files/config-libgcc-softfp.patch

Into one patch.  There are some changes to libgcc/config.host in
gcc-8.2.0 that required updating the patch to that file.  There's some
common code to handle soft-fp on x86.  In gcc-8.2.0 that common code
would by default get applied to a zephyr build.  However the common
code doesn't handle soft-fp the way we need so we add
i[34567]86-zephyr-elf as a special case similar to
i[34567]86-*-elfiamcu.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>

Author: galak

gcc/config.gcc

@@ -1895,6 +1895,10 @@ x86_64-*-darwin*)
 i[34567]86-*-elfiamcu)
 	tm_file="${tm_file} i386/unix.h i386/att.h dbxelf.h elfos.h newlib-stdint.h i386/iamcu.h"
 	;;
+i586-zephyr-elf)
+	tm_file="${tm_file} i386/unix.h i386/att.h dbxelf.h elfos.h newlib-stdint.h i386/i386elf.h"
+	tmake_file="${tmake_file} i386/t-zephyr"
+	;;
 i[34567]86-*-elf*)
 	tm_file="${tm_file} i386/unix.h i386/att.h dbxelf.h elfos.h newlib-stdint.h i386/i386elf.h"
 	;;

gcc/config/i386/t-zephyr

@@ -0,0 +1,23 @@
+# Copyright (C) 2016 Intel Corporation.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+#
+
+MULTILIB_OPTIONS += msoft-float
+MULTILIB_DIRNAMES += soft-float
+MULTILIB_MATCHES = msoft-float=mno-80387
+MULTILIB_EXCEPTIONS =

libgcc/config.host

@@ -711,6 +711,9 @@ x86_64-*-darwin*)
 i[34567]86-*-elfiamcu)
 	tmake_file="$tmake_file i386/t-crtstuff t-softfp-sfdftf i386/32/t-softfp i386/32/t-iamcu i386/t-softfp t-softfp t-dfprules"
 	;;
+i586-zephyr-elf)
+	tmake_file="$tmake_file i386/t-crtstuff t-softfp-sfdf i386/32/t-zephyr i386/t-softfp t-softfp t-dfprules"
+	;;
 i[34567]86-*-elf*)
 	tmake_file="$tmake_file i386/t-crtstuff t-crtstuff-pic t-libgcc-pic"
 	;;
@@ -1568,7 +1571,7 @@ i[34567]86-*-linux* | x86_64-*-linux* | \
 esac
 
 case ${host} in
-i[34567]86-*-elfiamcu | i[34567]86-*-rtems*)
+i[34567]86-*-elfiamcu | i[34567]86-zephyr-elf | i[34567]86-*-rtems*)
 	# These use soft-fp for SFmode and DFmode, not just TFmode.
 	;;
 i[34567]86-*-* | x86_64-*-*)

libgcc/config/i386/32/t-zephyr

@@ -0,0 +1 @@
+HOST_LIBGCC2_CFLAGS += -mlong-double-80