Revert "Revert "Upgrade to 5.0.71.48"" DO NOT MERGE

This reverts commit f2e3994fa5148cc3d9946666f0b0596290192b0e,
and updates the x64 makefile properly so it doesn't break that
build.

FPIIM-449

Change-Id: Ib83e35bfbae6af627451c926a9650ec57c045605
(cherry picked from commit 109988c7ccb6f3fd1a58574fa3dfb88beaef6632)
diff --git a/third_party/llvm-build/Release+Asserts/lib/clang/3.9.0/asan_blacklist.txt b/third_party/llvm-build/Release+Asserts/lib/clang/3.9.0/asan_blacklist.txt
new file mode 100644
index 0000000..c25921f
--- /dev/null
+++ b/third_party/llvm-build/Release+Asserts/lib/clang/3.9.0/asan_blacklist.txt
@@ -0,0 +1,13 @@
+# Blacklist for AddressSanitizer. Turns off instrumentation of particular
+# functions or sources. Use with care. You may set location of blacklist
+# at compile-time using -fsanitize-blacklist=<path> flag.
+
+# Example usage:
+# fun:*bad_function_name*
+# src:file_with_tricky_code.cc
+# global:*global_with_bad_access_or_initialization*
+# global:*global_with_initialization_issues*=init
+# type:*Namespace::ClassName*=init
+
+# Stack buffer overflow in VC/INCLUDE/xlocnum, see http://goo.gl/L4qqUG
+fun:*_Find_elem@*@std*