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/include/stdatomic.h b/third_party/llvm-build/Release+Asserts/lib/clang/3.9.0/include/stdatomic.h
new file mode 100644
index 0000000..e037987
--- /dev/null
+++ b/third_party/llvm-build/Release+Asserts/lib/clang/3.9.0/include/stdatomic.h
@@ -0,0 +1,190 @@
+/*===---- stdatomic.h - Standard header for atomic types and operations -----===
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef __CLANG_STDATOMIC_H
+#define __CLANG_STDATOMIC_H
+
+/* If we're hosted, fall back to the system's stdatomic.h. FreeBSD, for
+ * example, already has a Clang-compatible stdatomic.h header.
+ */
+#if __STDC_HOSTED__ && __has_include_next(<stdatomic.h>)
+# include_next <stdatomic.h>
+#else
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* 7.17.1 Introduction */
+
+#define ATOMIC_BOOL_LOCK_FREE       __GCC_ATOMIC_BOOL_LOCK_FREE
+#define ATOMIC_CHAR_LOCK_FREE       __GCC_ATOMIC_CHAR_LOCK_FREE
+#define ATOMIC_CHAR16_T_LOCK_FREE   __GCC_ATOMIC_CHAR16_T_LOCK_FREE
+#define ATOMIC_CHAR32_T_LOCK_FREE   __GCC_ATOMIC_CHAR32_T_LOCK_FREE
+#define ATOMIC_WCHAR_T_LOCK_FREE    __GCC_ATOMIC_WCHAR_T_LOCK_FREE
+#define ATOMIC_SHORT_T_LOCK_FREE    __GCC_ATOMIC_SHORT_T_LOCK_FREE
+#define ATOMIC_INT_T_LOCK_FREE      __GCC_ATOMIC_INT_T_LOCK_FREE
+#define ATOMIC_LONG_T_LOCK_FREE     __GCC_ATOMIC_LONG_T_LOCK_FREE
+#define ATOMIC_LLONG_T_LOCK_FREE    __GCC_ATOMIC_LLONG_T_LOCK_FREE
+#define ATOMIC_POINTER_T_LOCK_FREE  __GCC_ATOMIC_POINTER_T_LOCK_FREE
+
+/* 7.17.2 Initialization */
+
+#define ATOMIC_VAR_INIT(value) (value)
+#define atomic_init __c11_atomic_init
+
+/* 7.17.3 Order and consistency */
+
+typedef enum memory_order {
+  memory_order_relaxed = __ATOMIC_RELAXED,
+  memory_order_consume = __ATOMIC_CONSUME,
+  memory_order_acquire = __ATOMIC_ACQUIRE,
+  memory_order_release = __ATOMIC_RELEASE,
+  memory_order_acq_rel = __ATOMIC_ACQ_REL,
+  memory_order_seq_cst = __ATOMIC_SEQ_CST
+} memory_order;
+
+#define kill_dependency(y) (y)
+
+/* 7.17.4 Fences */
+
+/* These should be provided by the libc implementation. */
+void atomic_thread_fence(memory_order);
+void atomic_signal_fence(memory_order);
+
+#define atomic_thread_fence(order) __c11_atomic_thread_fence(order)
+#define atomic_signal_fence(order) __c11_atomic_signal_fence(order)
+
+/* 7.17.5 Lock-free property */
+
+#define atomic_is_lock_free(obj) __c11_atomic_is_lock_free(sizeof(*(obj)))
+
+/* 7.17.6 Atomic integer types */
+
+#ifdef __cplusplus
+typedef _Atomic(bool)               atomic_bool;
+#else
+typedef _Atomic(_Bool)              atomic_bool;
+#endif
+typedef _Atomic(char)               atomic_char;
+typedef _Atomic(signed char)        atomic_schar;
+typedef _Atomic(unsigned char)      atomic_uchar;
+typedef _Atomic(short)              atomic_short;
+typedef _Atomic(unsigned short)     atomic_ushort;
+typedef _Atomic(int)                atomic_int;
+typedef _Atomic(unsigned int)       atomic_uint;
+typedef _Atomic(long)               atomic_long;
+typedef _Atomic(unsigned long)      atomic_ulong;
+typedef _Atomic(long long)          atomic_llong;
+typedef _Atomic(unsigned long long) atomic_ullong;
+typedef _Atomic(uint_least16_t)     atomic_char16_t;
+typedef _Atomic(uint_least32_t)     atomic_char32_t;
+typedef _Atomic(wchar_t)            atomic_wchar_t;
+typedef _Atomic(int_least8_t)       atomic_int_least8_t;
+typedef _Atomic(uint_least8_t)      atomic_uint_least8_t;
+typedef _Atomic(int_least16_t)      atomic_int_least16_t;
+typedef _Atomic(uint_least16_t)     atomic_uint_least16_t;
+typedef _Atomic(int_least32_t)      atomic_int_least32_t;
+typedef _Atomic(uint_least32_t)     atomic_uint_least32_t;
+typedef _Atomic(int_least64_t)      atomic_int_least64_t;
+typedef _Atomic(uint_least64_t)     atomic_uint_least64_t;
+typedef _Atomic(int_fast8_t)        atomic_int_fast8_t;
+typedef _Atomic(uint_fast8_t)       atomic_uint_fast8_t;
+typedef _Atomic(int_fast16_t)       atomic_int_fast16_t;
+typedef _Atomic(uint_fast16_t)      atomic_uint_fast16_t;
+typedef _Atomic(int_fast32_t)       atomic_int_fast32_t;
+typedef _Atomic(uint_fast32_t)      atomic_uint_fast32_t;
+typedef _Atomic(int_fast64_t)       atomic_int_fast64_t;
+typedef _Atomic(uint_fast64_t)      atomic_uint_fast64_t;
+typedef _Atomic(intptr_t)           atomic_intptr_t;
+typedef _Atomic(uintptr_t)          atomic_uintptr_t;
+typedef _Atomic(size_t)             atomic_size_t;
+typedef _Atomic(ptrdiff_t)          atomic_ptrdiff_t;
+typedef _Atomic(intmax_t)           atomic_intmax_t;
+typedef _Atomic(uintmax_t)          atomic_uintmax_t;
+
+/* 7.17.7 Operations on atomic types */
+
+#define atomic_store(object, desired) __c11_atomic_store(object, desired, __ATOMIC_SEQ_CST)
+#define atomic_store_explicit __c11_atomic_store
+
+#define atomic_load(object) __c11_atomic_load(object, __ATOMIC_SEQ_CST)
+#define atomic_load_explicit __c11_atomic_load
+
+#define atomic_exchange(object, desired) __c11_atomic_exchange(object, desired, __ATOMIC_SEQ_CST)
+#define atomic_exchange_explicit __c11_atomic_exchange
+
+#define atomic_compare_exchange_strong(object, expected, desired) __c11_atomic_compare_exchange_strong(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
+#define atomic_compare_exchange_strong_explicit __c11_atomic_compare_exchange_strong
+
+#define atomic_compare_exchange_weak(object, expected, desired) __c11_atomic_compare_exchange_weak(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
+#define atomic_compare_exchange_weak_explicit __c11_atomic_compare_exchange_weak
+
+#define atomic_fetch_add(object, operand) __c11_atomic_fetch_add(object, operand, __ATOMIC_SEQ_CST)
+#define atomic_fetch_add_explicit __c11_atomic_fetch_add
+
+#define atomic_fetch_sub(object, operand) __c11_atomic_fetch_sub(object, operand, __ATOMIC_SEQ_CST)
+#define atomic_fetch_sub_explicit __c11_atomic_fetch_sub
+
+#define atomic_fetch_or(object, operand) __c11_atomic_fetch_or(object, operand, __ATOMIC_SEQ_CST)
+#define atomic_fetch_or_explicit __c11_atomic_fetch_or
+
+#define atomic_fetch_xor(object, operand) __c11_atomic_fetch_xor(object, operand, __ATOMIC_SEQ_CST)
+#define atomic_fetch_xor_explicit __c11_atomic_fetch_xor
+
+#define atomic_fetch_and(object, operand) __c11_atomic_fetch_and(object, operand, __ATOMIC_SEQ_CST)
+#define atomic_fetch_and_explicit __c11_atomic_fetch_and
+
+/* 7.17.8 Atomic flag type and operations */
+
+typedef struct atomic_flag { atomic_bool _Value; } atomic_flag;
+
+#define ATOMIC_FLAG_INIT { 0 }
+
+/* These should be provided by the libc implementation. */
+#ifdef __cplusplus
+bool atomic_flag_test_and_set(volatile atomic_flag *);
+bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
+#else
+_Bool atomic_flag_test_and_set(volatile atomic_flag *);
+_Bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
+#endif
+void atomic_flag_clear(volatile atomic_flag *);
+void atomic_flag_clear_explicit(volatile atomic_flag *, memory_order);
+
+#define atomic_flag_test_and_set(object) __c11_atomic_exchange(&(object)->_Value, 1, __ATOMIC_SEQ_CST)
+#define atomic_flag_test_and_set_explicit(object, order) __c11_atomic_exchange(&(object)->_Value, 1, order)
+
+#define atomic_flag_clear(object) __c11_atomic_store(&(object)->_Value, 0, __ATOMIC_SEQ_CST)
+#define atomic_flag_clear_explicit(object, order) __c11_atomic_store(&(object)->_Value, 0, order)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __STDC_HOSTED__ */
+#endif /* __CLANG_STDATOMIC_H */
+