This patch ensures __clear_cache is not called on arm.  In earlier versions of
clang, this special builtin was emitted as a function call, leading to link
errors.

Introduced here: http://svnweb.freebsd.org/changeset/base/243830

Index: lib/Support/Unix/Memory.inc
===================================================================
--- lib/Support/Unix/Memory.inc
+++ lib/Support/Unix/Memory.inc
@@ -332,7 +332,7 @@ void Memory::InvalidateInstructionCache(const void
   for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
     asm volatile("icbi 0, %0" : : "r"(Line));
   asm volatile("isync");
-#  elif (defined(__arm__) || defined(__aarch64__)) && defined(__GNUC__)
+#  elif (defined(__arm__) || defined(__aarch64__)) && defined(__GNUC__) && !defined(__FreeBSD__)
   // FIXME: Can we safely always call this for __GNUC__ everywhere?
   const char *Start = static_cast<const char *>(Addr);
   const char *End = Start + Len;