Update prebuilt Clang to r416183b from Android.

https://android.googlesource.com/platform/prebuilts/clang/host/
linux-x86/+/06a71ddac05c22edb2d10b590e1769b3f8619bef

clang 12.0.5 (based on r416183b) from build 7284624.

Change-Id: I277a316abcf47307562d8b748b84870f31a72866
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/linux-x64/clang/include/llvm/Support/SwapByteOrder.h b/linux-x64/clang/include/llvm/Support/SwapByteOrder.h
index 06a447a..e8612ba 100644
--- a/linux-x64/clang/include/llvm/Support/SwapByteOrder.h
+++ b/linux-x64/clang/include/llvm/Support/SwapByteOrder.h
@@ -14,20 +14,43 @@
 #ifndef LLVM_SUPPORT_SWAPBYTEORDER_H
 #define LLVM_SUPPORT_SWAPBYTEORDER_H
 
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/DataTypes.h"
 #include <cstddef>
+#include <cstdint>
 #include <type_traits>
 #if defined(_MSC_VER) && !defined(_DEBUG)
 #include <stdlib.h>
 #endif
 
-namespace llvm {
-namespace sys {
+#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__) ||            \
+    defined(__Fuchsia__) || defined(__EMSCRIPTEN__)
+#include <endian.h>
+#elif defined(_AIX)
+#include <sys/machine.h>
+#elif defined(__sun)
+/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */
+#include <sys/types.h>
+#define BIG_ENDIAN 4321
+#define LITTLE_ENDIAN 1234
+#if defined(_BIG_ENDIAN)
+#define BYTE_ORDER BIG_ENDIAN
+#else
+#define BYTE_ORDER LITTLE_ENDIAN
+#endif
+#elif defined(__MVS__)
+#define BIG_ENDIAN 4321
+#define LITTLE_ENDIAN 1234
+#define BYTE_ORDER BIG_ENDIAN
+#else
+#if !defined(BYTE_ORDER) && !defined(_WIN32)
+#include <machine/endian.h>
+#endif
+#endif
 
-/// SwapByteOrder_16 - This function returns a byte-swapped representation of
+namespace llvm {
+
+/// ByteSwap_16 - This function returns a byte-swapped representation of
 /// the 16-bit argument.
-inline uint16_t SwapByteOrder_16(uint16_t value) {
+inline uint16_t ByteSwap_16(uint16_t value) {
 #if defined(_MSC_VER) && !defined(_DEBUG)
   // The DLL version of the runtime lacks these functions (bug!?), but in a
   // release build they're replaced with BSWAP instructions anyway.
@@ -39,10 +62,9 @@
 #endif
 }
 
-/// SwapByteOrder_32 - This function returns a byte-swapped representation of
-/// the 32-bit argument.
-inline uint32_t SwapByteOrder_32(uint32_t value) {
-#if defined(__llvm__) || (LLVM_GNUC_PREREQ(4, 3, 0) && !defined(__ICC))
+/// This function returns a byte-swapped representation of the 32-bit argument.
+inline uint32_t ByteSwap_32(uint32_t value) {
+#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC))
   return __builtin_bswap32(value);
 #elif defined(_MSC_VER) && !defined(_DEBUG)
   return _byteswap_ulong(value);
@@ -55,45 +77,55 @@
 #endif
 }
 
-/// SwapByteOrder_64 - This function returns a byte-swapped representation of
-/// the 64-bit argument.
-inline uint64_t SwapByteOrder_64(uint64_t value) {
-#if defined(__llvm__) || (LLVM_GNUC_PREREQ(4, 3, 0) && !defined(__ICC))
+/// This function returns a byte-swapped representation of the 64-bit argument.
+inline uint64_t ByteSwap_64(uint64_t value) {
+#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC))
   return __builtin_bswap64(value);
 #elif defined(_MSC_VER) && !defined(_DEBUG)
   return _byteswap_uint64(value);
 #else
-  uint64_t Hi = SwapByteOrder_32(uint32_t(value));
-  uint32_t Lo = SwapByteOrder_32(uint32_t(value >> 32));
+  uint64_t Hi = ByteSwap_32(uint32_t(value));
+  uint32_t Lo = ByteSwap_32(uint32_t(value >> 32));
   return (Hi << 32) | Lo;
 #endif
 }
 
+namespace sys {
+
+#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
+constexpr bool IsBigEndianHost = true;
+#else
+constexpr bool IsBigEndianHost = false;
+#endif
+
+static const bool IsLittleEndianHost = !IsBigEndianHost;
+
 inline unsigned char  getSwappedBytes(unsigned char C) { return C; }
 inline   signed char  getSwappedBytes(signed char C) { return C; }
 inline          char  getSwappedBytes(char C) { return C; }
 
-inline unsigned short getSwappedBytes(unsigned short C) { return SwapByteOrder_16(C); }
-inline   signed short getSwappedBytes(  signed short C) { return SwapByteOrder_16(C); }
+inline unsigned short getSwappedBytes(unsigned short C) { return ByteSwap_16(C); }
+inline   signed short getSwappedBytes(  signed short C) { return ByteSwap_16(C); }
 
-inline unsigned int   getSwappedBytes(unsigned int   C) { return SwapByteOrder_32(C); }
-inline   signed int   getSwappedBytes(  signed int   C) { return SwapByteOrder_32(C); }
+inline unsigned int   getSwappedBytes(unsigned int   C) { return ByteSwap_32(C); }
+inline   signed int   getSwappedBytes(  signed int   C) { return ByteSwap_32(C); }
 
-#if __LONG_MAX__ == __INT_MAX__
-inline unsigned long  getSwappedBytes(unsigned long  C) { return SwapByteOrder_32(C); }
-inline   signed long  getSwappedBytes(  signed long  C) { return SwapByteOrder_32(C); }
-#elif __LONG_MAX__ == __LONG_LONG_MAX__
-inline unsigned long  getSwappedBytes(unsigned long  C) { return SwapByteOrder_64(C); }
-inline   signed long  getSwappedBytes(  signed long  C) { return SwapByteOrder_64(C); }
-#else
-#error "Unknown long size!"
-#endif
+inline unsigned long getSwappedBytes(unsigned long C) {
+  // Handle LLP64 and LP64 platforms.
+  return sizeof(long) == sizeof(int) ? ByteSwap_32((uint32_t)C)
+                                     : ByteSwap_64((uint64_t)C);
+}
+inline signed long getSwappedBytes(signed long C) {
+  // Handle LLP64 and LP64 platforms.
+  return sizeof(long) == sizeof(int) ? ByteSwap_32((uint32_t)C)
+                                     : ByteSwap_64((uint64_t)C);
+}
 
 inline unsigned long long getSwappedBytes(unsigned long long C) {
-  return SwapByteOrder_64(C);
+  return ByteSwap_64(C);
 }
 inline signed long long getSwappedBytes(signed long long C) {
-  return SwapByteOrder_64(C);
+  return ByteSwap_64(C);
 }
 
 inline float getSwappedBytes(float C) {
@@ -102,7 +134,7 @@
     float f;
   } in, out;
   in.f = C;
-  out.i = SwapByteOrder_32(in.i);
+  out.i = ByteSwap_32(in.i);
   return out.f;
 }
 
@@ -112,15 +144,14 @@
     double d;
   } in, out;
   in.d = C;
-  out.i = SwapByteOrder_64(in.i);
+  out.i = ByteSwap_64(in.i);
   return out.d;
 }
 
 template <typename T>
-inline typename std::enable_if<std::is_enum<T>::value, T>::type
-getSwappedBytes(T C) {
+inline std::enable_if_t<std::is_enum<T>::value, T> getSwappedBytes(T C) {
   return static_cast<T>(
-      getSwappedBytes(static_cast<typename std::underlying_type<T>::type>(C)));
+      getSwappedBytes(static_cast<std::underlying_type_t<T>>(C)));
 }
 
 template<typename T>