llvm/test/tools/llvm-size/unknown-format.test

## Show that the an error is emitted if an unknown value is passed to --format.

# RUN: not llvm-size --format=unknown 2>&1 | FileCheck %s
# CHECK: {{.*}}llvm-size{{.*}}: error: --format value should be one of: 'berkeley', 'darwin', 'sysv'