Update Clang for rebase to r212749.

This also fixes a small issue with arm_neon.h not being generated always.

Includes a cherry-pick of:
r213450 - fixes mac-specific header issue
r213126 - removes a default -Bsymbolic on Android

Change-Id: I2a790a0f5d3b2aab11de596fc3a74e7cbc99081d
diff --git a/test/CodeGenCXX/const-init-cxx11.cpp b/test/CodeGenCXX/const-init-cxx11.cpp
index 1905933..d99b184 100644
--- a/test/CodeGenCXX/const-init-cxx11.cpp
+++ b/test/CodeGenCXX/const-init-cxx11.cpp
@@ -532,10 +532,10 @@
     // CHECK: call void @_ZN13InitFromConst7consumeIdEEvT_(double 4.300000e+00)
     consume(d);
 
-    // CHECK: call void @_ZN13InitFromConst7consumeIRKNS_1SEEEvT_(%"struct.InitFromConst::S"* @_ZN13InitFromConstL1sE)
+    // CHECK: call void @_ZN13InitFromConst7consumeIRKNS_1SEEEvT_(%"struct.InitFromConst::S"* nonnull @_ZN13InitFromConstL1sE)
     consume<const S&>(s);
 
-    // CHECK: call void @_ZN13InitFromConst7consumeIRKNS_1SEEEvT_(%"struct.InitFromConst::S"* @_ZN13InitFromConstL1sE)
+    // CHECK: call void @_ZN13InitFromConst7consumeIRKNS_1SEEEvT_(%"struct.InitFromConst::S"* nonnull @_ZN13InitFromConstL1sE)
     consume<const S&>(r);
 
     // CHECK: call void @_ZN13InitFromConst7consumeIPKNS_1SEEEvT_(%"struct.InitFromConst::S"* @_ZN13InitFromConstL1sE)