llvm-cov: test: add xfail for the big-endian buildbots

llvm-svn: 216310
diff --git a/llvm/test/tools/llvm-cov/showHighlightedRanges.cpp b/llvm/test/tools/llvm-cov/showHighlightedRanges.cpp
index 7c38fff..ce64fdd 100644
--- a/llvm/test/tools/llvm-cov/showHighlightedRanges.cpp
+++ b/llvm/test/tools/llvm-cov/showHighlightedRanges.cpp
@@ -43,3 +43,6 @@
   func2(9);
   return 0;
 }
+
+// llvm-cov doesn't work on big endian yet
+// XFAIL: powerpc64-, s390x, mips-, mips64-, sparc