Use the same ABI logic for AArch64 Big Endian as in other places
covering polys.

llvm-svn: 291437
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 9c90295..49208e2 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -1242,7 +1242,8 @@
     QualType RHSTy = RHS.get()->getType();
 
     llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
-    bool IsPolyUnsigned = Arch == llvm::Triple::aarch64;
+    bool IsPolyUnsigned = Arch == llvm::Triple::aarch64 ||
+                          Arch == llvm::Triple::aarch64_be;
     bool IsInt64Long =
         Context.getTargetInfo().getInt64Type() == TargetInfo::SignedLong;
     QualType EltTy =