Warning for "confusable" types

Hi internals, Something I've seen play out a couple of times: Newbies try to use something like "integer" or "resource" as a type, and then get a confusing error message along the lines of "must be an instance of resource, resource given". I would like to throw a compiler warning in this case, that looks as one of the following: > Warning: "integer" will be interpreted as a class type. Did you mean "int"? Use qualified name or "use" to suppress this warning > Warning: "resource" is not a supported builtin type and will be interpreted as a class type. Use qualified name or "use" to suppress this warning This warning only triggers if the type is lowercase (integer but not Integer), is unqualified (integer but not \integer) and is not imported (there is no "use integer"). This provides multiple ways to avoid the warning for code that does legitimately want to use lowercase "integer" as a class type. Implementation: https://github.com/php/php-src/pull/4815 Thoughts? Nikita