Update to a LLVM 5.0-ish version from trunk

Using the 5.0 release branch should work equally well except for
aarch64/win support.

patches/mingw-0002.patch

@@ -1,30 +0,0 @@
-From 5592b70cca64935b0d090fe5030b3110ba17068c Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?Hugo=20Beauz=C3=A9e-Luyssen?= <hugo@beauzee.fr>
-Date: Fri, 13 May 2016 15:17:56 +0200
-Subject: [PATCH] yvals.h: Don't create a _Bool typedef if a macro already
- exists
-
----
- mingw-w64-headers/crt/yvals.h | 2 ++
- 1 file changed, 2 insertions(+)
-
-diff --git a/mingw-w64-headers/crt/yvals.h b/mingw-w64-headers/crt/yvals.h
-index 70593c4..98b6921 100644
---- a/mingw-w64-headers/crt/yvals.h
-+++ b/mingw-w64-headers/crt/yvals.h
-@@ -163,10 +163,12 @@
- #define _Restrict __restrict__
- 
- #ifdef __cplusplus
-+#ifndef _Bool
- _STD_BEGIN
- typedef bool _Bool;
- _STD_END
- #endif
-+#endif
- 
- #define _LONGLONG /* __MINGW_EXTENSION */ __int64
- #define _ULONGLONG /* __MINGW_EXTENSION */ unsigned __int64
--- 
-2.8.1
-