Find a replacement for indirect field reference

[Richard Gibson]

ECMA-262 editors are opposed to accepting Record [[<fieldName>]] syntax, and for good reason. We should strive to minimize its use in ECMA-402, and ideally eliminate it altogether. One possibility that comes to mind is introduction of a Dictionary specification type, such that record.[[<fieldName>]] could be replaced with e.g. dict[fieldName] or DictionaryGet(dict, fieldName). This would also improve our ability to address #81, in particular by separating spec values that have static keys (which would mostly remain Records) from those with dynamic keys such as the values of constructor [[LocaleData]] slots (which would become Dictionaries).

[Ujjwal Sharma]

@gibson042 the idea of introducing dictionaries to avoid using records like this makes a lot of sense to me. If it's acceptable to the 262 editors and can be added to ecmarkup, let's do it.