lang/gcc12: Fix Address sanitizer

Software compiled with -fsanitize=address fails to run with the error
message "ASan runtime does not come first in initial library list; you
should either link runtime to your application or manually preload it
with LD_PRELOAD".

This commit fixes the issue by ignoring the [vdso] loaded shared library
instead of linux-vdso.so.

PR:		267751
Reported by:	yuri

lang/gcc12/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	gcc
 PORTVERSION=	12.2.0
-PORTREVISION=	3
+PORTREVISION=	4
 CATEGORIES=	lang
 MASTER_SITES=	GCC
 PKGNAMESUFFIX=	${SUFFIX}

lang/gcc12/files/patch-libsanitizer_asan_asan__linux.cpp

@@ -0,0 +1,18 @@
+Since the vDSO shared librares on Linux and FreeBSD are called
+differently, the initialization order check fails on FreeBSD.
+This patch fixes it by ignoring [vdso] instead of linux-vdso.so.
+
+GCC gets the original file from the LLVM Project, so this patch should
+probably be upstreamed directly to the LLVM Project rather than to GCC.
+
+--- libsanitizer/asan/asan_linux.cpp.orig	2022-11-23 10:52:45 UTC
++++ libsanitizer/asan/asan_linux.cpp
+@@ -135,7 +135,7 @@ static int FindFirstDSOCallback(struct dl_phdr_info *i
+     return 0;
+ 
+   // Ignore vDSO
+-  if (internal_strncmp(info->dlpi_name, "linux-", sizeof("linux-") - 1) == 0)
++  if (internal_strncmp(info->dlpi_name, "[vdso]", sizeof("[vdso]") - 1) == 0)
+     return 0;
+ 
+ #if SANITIZER_FREEBSD || SANITIZER_NETBSD