gcc8snapshot: Fix build with Clang

[Kamil Rytarowski <n54%gmx.com@localhost>]

Module Name:	pkgsrc-wip
Committed By:	Kamil Rytarowski <n54%gmx.com@localhost>
Pushed By:	kamil
Date:		Wed Oct 25 00:13:09 2017 +0200
Changeset:	59143f6de72152c58ef87f3868aa58080baddf5f

Modified Files:
	gcc8snapshot/distinfo
Added Files:
	gcc8snapshot/patches/patch-libbacktrace_elf.c

Log Message:
gcc8snapshot: Fix build with Clang

../../../../gcc-8-20171022/libsanitizer/libbacktrace/../../libbacktrace/elf.c: In function 'elf_is_symlink':
../../../../gcc-8-20171022/libsanitizer/libbacktrace/../../libbacktrace/elf.c:740:21: error: 'st.st_mode' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   return S_ISLNK (st.st_mode);
                     ^
cc1: all warnings being treated as errors

To see a diff of this commit:
https://wip.pkgsrc.org/cgi-bin/gitweb.cgi?p=pkgsrc-wip.git;a=commitdiff;h=59143f6de72152c58ef87f3868aa58080baddf5f

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

diffstat:
 gcc8snapshot/distinfo                         |  1 +
 gcc8snapshot/patches/patch-libbacktrace_elf.c | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diffs:
diff --git a/gcc8snapshot/distinfo b/gcc8snapshot/distinfo
index 3e73efc75b..115c4c2fcf 100644
--- a/gcc8snapshot/distinfo
+++ b/gcc8snapshot/distinfo
@@ -20,6 +20,7 @@ SHA1 (patch-gcc_ggc-common.c) = a5d2dba635859f5d680c3f80d7c30b42461c752b
 SHA1 (patch-gcc_lto_lto.c) = 825b632e2a7ff5777d4fbfdcf6f0ea3f64c4742b
 SHA1 (patch-gcc_system.h) = 4c959a6b1c4d524cbdf44cfb80f0e5758ec20783
 SHA1 (patch-isl_configure) = 36b37778ee13c0b364fb24d5864d6a9e65b29b7d
+SHA1 (patch-libbacktrace_elf.c) = d356661933e3cd9ef694b8472c3d03feca8b44cd
 SHA1 (patch-libcilkrts_configure) = 6c2d0f897c4a451d5b4b4fb5b3415d04704c0b0d
 SHA1 (patch-libcilkrts_runtime_os-unix.c) = b25632587d9fbe8ff38377fe34cb16225355b521
 SHA1 (patch-libdecnumber_decNumber.c) = cec90e49c829bfc6ba1ec605d2fac7daaad62762
diff --git a/gcc8snapshot/patches/patch-libbacktrace_elf.c b/gcc8snapshot/patches/patch-libbacktrace_elf.c
new file mode 100644
index 0000000000..2999f141e9
--- /dev/null
+++ b/gcc8snapshot/patches/patch-libbacktrace_elf.c
@@ -0,0 +1,13 @@
+$NetBSD$
+
+--- libbacktrace/elf.c.orig	2017-10-05 16:39:38.000000000 +0000
++++ libbacktrace/elf.c
+@@ -733,7 +733,7 @@ elf_syminfo (struct backtrace_state *sta
+ static int
+ elf_is_symlink (const char *filename)
+ {
+-  struct stat st;
++  struct stat st = {0};
+ 
+   if (lstat (filename, &st) < 0)
+     return 0;