Add a test case for the crash fixed with r267037. David Blaikie said it would be nice to have!

This was crashing llvm-objdump with -macho -objc-meta-data when trying dump a non-existent section.
So the test binary is simply created from an empty .s file compiled with: clang -arch armv7 empty.s -c

llvm-svn: 267782

Author: enderby

llvm/test/tools/llvm-objdump/Inputs/empty.macho-armv7

@@ -0,0 +1,3 @@
+# RUN: llvm-objdump -macho -objc-meta-data %p/Inputs/empty.macho-armv7 | FileCheck %s
+
+# CHECK: empty.macho-armv7: