gcc: Add gcc 12 snapshot

This commit is identical to what I have submitted upstream and what has since been picked up by upstream devs.

It is not yet committed upstream because upstream would rather wait for an official gcc 12-rc, but upstream's gcc 12 will have the same patches when it arrives.

Signed-off-by: Bernhard Rosenkränzer bernhard.rosenkraenzer.ext@huawei.com

meta-oniro-staging/recipes-devtools/gcc/gcc/0001-Fix-install-path-of-linux64.h.patch

+From 58211c7ceb0510b2a11a7f1da3c7fa968c658749 Mon Sep 17 00:00:00 2001
+From: Andrei Gherzan <andrei.gherzan@huawei.com>
+Date: Wed, 22 Dec 2021 12:49:25 +0100
+Subject: [PATCH] Fix install path of linux64.h
+
+We add linux64.h to tm includes[1] as a relative path to B. This patch
+adapts the install path of linux64.h to match the include in tm.h.
+
+[1] 0016-Use-the-multilib-config-files-from-B-instead-of-usin.patch
+
+Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>
+
+Upstream-Status: Inappropriate [configuration]
+---
+ gcc/Makefile.in | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/gcc/Makefile.in b/gcc/Makefile.in
+index 9b17d120a..d175ec4e3 100644
+--- a/gcc/Makefile.in
++++ b/gcc/Makefile.in
+@@ -3693,6 +3693,8 @@ install-plugin: installdirs lang.install-plugin s-header-vars install-gengtype
+ 	  "$(srcdir)"/config/* | "$(srcdir)"/common/config/* \
+ 	  | "$(srcdir)"/c-family/* | "$(srcdir)"/*.def ) \
+ 	    base=`echo "$$path" | sed -e "s|$$srcdirstrip/||"`;; \
++	  */linux64.h ) \
++	    base=`dirname $$path`;;\
+ 	  *) base=`basename $$path` ;; \
+ 	  esac; \
+ 	  dest=$(plugin_includedir)/$$base; \
+-- 
+2.25.1
+