add OpenBSD defs to llvm aarch64 target

[Jonathan Gray]

Same change patrick made to llvm in base.

With this aarch64-unknown-openbsd6.0 defines now include

#define __ELF__ 1
#define __OpenBSD__ 1
#define __unix 1
#define __unix__ 1
#define unix 1

Index: Makefile
===================================================================
RCS file: /cvs/ports/devel/llvm/Makefile,v
retrieving revision 1.125
diff -u -p -r1.125 Makefile
--- Makefile    2 Nov 2016 07:46:33 -0000       1.125
+++ Makefile    19 Dec 2016 10:39:28 -0000
@@ -11,7 +11,7 @@ COMMENT =     modular, fast C/C++/ObjC compi
 LLVM_V =       3.9.0
 DISTNAME =     llvm-${LLVM_V}.src
 PKGNAME =      llvm-${LLVM_V}
-REVISION =     2
+REVISION =     3
 CATEGORIES =   devel
 DISTFILES =    llvm-${LLVM_V}.src${EXTRACT_SUFX} \
                cfe-${LLVM_V}.src${EXTRACT_SUFX} \
Index: patches/patch-tools_clang_lib_Basic_Targets_cpp
===================================================================
RCS file: 
/cvs/ports/devel/llvm/patches/patch-tools_clang_lib_Basic_Targets_cpp,v
retrieving revision 1.17
diff -u -p -r1.17 patch-tools_clang_lib_Basic_Targets_cpp
--- patches/patch-tools_clang_lib_Basic_Targets_cpp     7 Oct 2016 08:55:30 
-0000       1.17
+++ patches/patch-tools_clang_lib_Basic_Targets_cpp     19 Dec 2016 10:50:39 
-0000
@@ -3,9 +3,10 @@ $OpenBSD: patch-tools_clang_lib_Basic_Ta
 - Enable __float128 support on X86
 - [OpenBSD] Add type sign information for OpenBSD
 - Set ABI for ARM
+- [OpenBSD] set OpenBSD defines for aarch64
 
---- tools/clang/lib/Basic/Targets.cpp.orig     Mon Jul 25 12:21:28 2016
-+++ tools/clang/lib/Basic/Targets.cpp  Sat Sep 24 12:02:09 2016
+--- tools/clang/lib/Basic/Targets.cpp.orig     Tue Jul 26 02:21:28 2016
++++ tools/clang/lib/Basic/Targets.cpp  Mon Dec 19 21:48:14 2016
 @@ -531,6 +531,8 @@ class OpenBSDTargetInfo : public OSTargetInfo<Target> 
      Builder.defineMacro("__ELF__");
      if (Opts.POSIXThreads)
@@ -64,3 +65,12 @@ $OpenBSD: patch-tools_clang_lib_Basic_Ta
          else
            setABI("aapcs");
          break;
+@@ -8148,6 +8159,8 @@ static TargetInfo *AllocateTarget(const llvm::Triple &
+       return new LinuxTargetInfo<AArch64leTargetInfo>(Triple, Opts);
+     case llvm::Triple::NetBSD:
+       return new NetBSDTargetInfo<AArch64leTargetInfo>(Triple, Opts);
++    case llvm::Triple::OpenBSD:
++      return new OpenBSDTargetInfo<AArch64leTargetInfo>(Triple, Opts);
+     default:
+       return new AArch64leTargetInfo(Triple, Opts);
+     }