Formula factory: re-raise certain NameErrors.

Some name errors, such as NoMethodError, represent programming errors.
Re-raise them to get a usable error message.

Closes Homebrew/homebrew#14467.

Library/Homebrew/formula.rb

@@ -405,6 +405,10 @@ class Formula
 
     return klass.new(name) if install_type == :from_name
     return klass.new(name, path.to_s)
+  rescue NoMethodError
+    # This is a programming error in an existing formula, and should not
+    # have a "no such formula" message.
+    raise
   rescue LoadError, NameError
     raise FormulaUnavailableError.new(name)
   end