Add simple soft-panic test

utils/make_panic_test.rb

@@ -0,0 +1,13 @@
+#!/usr/bin/env ruby
+
+crates = Dir["**/Cargo.toml"].sort!
+
+crates.each do |x|
+  next if x.include?('raspi3_boot')
+
+  x = File.dirname(x)
+  puts "\n" + x.to_s + ':'
+  Dir.chdir(x) do
+     system('make nm | grep panic_fmt')
+  end
+end