Previously, the early error prohibiting duplicate entries in
UniqueFormalParameters was only tested in terms of async functions. In
one case, this was misattributed to UniqeFormalParameters and only
enforced for strict mode code.

Extend coverage to the other function-creating productions which include
UniqueFormalParameters (i.e. method definitions and non-async arrow
functions), and update the existing tests to more accurately describe
the source of the error.

Closes #1634.

Early errors may result from parsing the source text of a test file, but
they may also result from parsing some other source text as referenced
through the ES2015 module syntax. The latter form of early error is not
necessarily detectable by ECMAScript parsers, however. Because of this,
the label "early" is not sufficiently precise for all Test262 consumers
to correctly interpret all tests.

Update the "phase" name of "early" to "parse" for all those negative
tests that describe errors resulting from parsing of the file's source
text directly. A forthcoming commit will update the remaining tests to
use a "phase" name that is more specific to module resolution.

This pattern makes expectations more explicit by making test files more
literal.

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.

Authored via the following command:

   $ find test -type f -print0 | \
       xargs -0 sed \
         -i 's/^\(\s*\)negative:\s*SyntaxError\s*$/\1negative:\n\1  phase: early\n\1  type: SyntaxError/g'

Closes #479