From the spec: https://tc39.es/ecma262/#sec-literals-numeric-literals
The SourceCharacter immediately following a NumericLiteral must not be
an IdentifierStart or DecimalDigit.
For example: 3in is an error and not the two input elements 3 and in.
The addition of assert functions to Userland/js
was done before we had load(..) implemented. Now
that it exists, it seems like the right move the
test helper functions to pure javascript instead
of poluting js with random global functions.
