[llvm-objdump] Add --file-headers (-f) option

llvm-svn: 336284
diff --git a/llvm/test/tools/llvm-objdump/file-headers-unsupported.test b/llvm/test/tools/llvm-objdump/file-headers-unsupported.test
new file mode 100644
index 0000000..f9fc118
--- /dev/null
+++ b/llvm/test/tools/llvm-objdump/file-headers-unsupported.test
@@ -0,0 +1,3 @@
+# RUN: not llvm-objdump -file-headers %p/Inputs/trivial.obj.wasm 2>&1 | FileCheck %s
+
+# CHECK: Invalid/Unsupported object file format