The templates are being used for many tests reusing the same available function forms.
The format they are provided allow us to extend tests with cases for other tests relying
in the same formats.

After @rwaldron's feedback:

The purpose of the `!` operator is to evaluate an UnaryExpression,
coerce the result to a boolean value and then return the negated
value of that operation. But that's not what you're trying to do at
all—you just want to evaluate the expression to the right of the
operator, nothing more, nothing less. In this specific case, you
don't even really care about the evaluation, the goal is write
valid (or invalid, as the case may be) syntax that is will be
parsed according to a specific grammar rule that requires some
operator to signal that the thing is an expression and not a Block
Statement.

Tests doesn't use async functionality and don't call $DONE, so remove
"async" flag:
- src/params/error/async-gen-named-func-expr.template
- test/language/expressions/async-generator/params-named-dflt-abrupt.js
- test/language/expressions/async-generator/params-named-dflt-ref-later.js
- test/language/expressions/async-generator/params-named-dflt-ref-self.js

Intl.PluralRules.prototype is no longer a Intl.Prototype instance:
- test/intl402/PluralRules/prototype/prototype.js

Intl.PluralRules throws an error when called as a function:
- test/intl402/PluralRules/undefined-newtarget-throws.js

Module namespace objects call OrdinaryDelete for symbol properties:
- test/language/module-code/namespace/internals/delete-non-exported.js

Async generators no longer retrieves "done" property twice:
- src/async-generators/yield-star-async-next.case
- src/async-generators/yield-star-async-return.case
- src/async-generators/yield-star-async-throw.case

Minor units of CLF is 4, so we need to test with maximumFractionDigits=3
to get an error:
- test/intl402/NumberFormat/dft-currency-mnfd-range-check-mxfd.js

DateTimeFormat.prototype.formatToParts length property was changed from
0 to 1:
- test/intl402/DateTimeFormat/prototype/formatToParts/length.js

minimumSignificantDigits and maximumSignificantDigits properties are
only retrieved once:
- test/intl402/NumberFormat/11.1.1_32.js

Fixes #904

Ref #822

Fix 850

Fixes #771