Update to GCC 9.3.0.

While here, switch i386 to assume a default architecture of "i686"
for FreeBSD 11+ to match clang.  This permits lldb to link without
needing libatomic.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D26205

devel/freebsd-gcc9/Makefile

@@ -1,8 +1,7 @@
 # $FreeBSD$
 
 PORTNAME=	gcc
-PORTVERSION=	9.2.0
-PORTREVISION=	1
+PORTVERSION=	9.3.0
 CATEGORIES=	devel
 MASTER_SITES=	GCC/releases/gcc-${DISTVERSION}
 PKGNAMEPREFIX=	${TARGETARCH}-
@@ -78,6 +77,10 @@ MAKE_ARGS+=CXXFLAGS=-fbracket-depth=512
 . endif
 .endif
 
+.if ${TARGETARCH} == "amd64" || ${TARGETARCH} == "powerpc64"
+CONFIGURE_ARGS+=--enable-multilib
+.endif
+
 .if ${ARCH} == "aarch64"
 PLIST_SUB+=	PLUGINS="@comment plugin does not build"
 .else

devel/freebsd-gcc9/distinfo

@@ -1,3 +1,3 @@
-TIMESTAMP = 1574959919
-SHA256 (gcc-9.2.0.tar.xz) = ea6ef08f121239da5695f76c9b33637a118dcf63e24164422231917fa61fb206
-SIZE (gcc-9.2.0.tar.xz) = 70607648
+TIMESTAMP = 1595179652
+SHA256 (gcc-9.3.0.tar.xz) = 71e197867611f6054aa1119b13a0c0abac12834765fe2d81f35ac57f84f742d1
+SIZE (gcc-9.3.0.tar.xz) = 70533868

devel/freebsd-gcc9/files/patch-i686

@@ -0,0 +1,13 @@
+--- gcc/config.gcc.orig	2020-08-19 09:37:17.455916000 -0700
++++ gcc/config.gcc	2020-08-19 10:19:33.883084000 -0700
+@@ -3346,7 +3346,9 @@ arch_without_sse2=no
+ arch_without_64bit=no
+ case ${target} in
+   i386-*-freebsd*)
+-    if test $fbsd_major -ge 6; then
++    if test $fbsd_major -ge 11; then
++      arch=i686
++    elif test $fbsd_major -ge 6; then
+       arch=i486
+     else
+       arch=i386