Stop representing quoted member functions as computed properties in the AST

[lauraharker]

Filing this after internal discussion with @concavelenz

Right now the compiler represents quoted member functions, e.g. class C { 'f'() {} }, the same way it represents computed property member functions: class C { ['f']() {} }.

This means that the compiler prints class C { ['f']() {} } if given class C { 'f'() {} }: example.

This does not align with how we treat quoted regular object literal properties, getters, and setters. Those have a special 'quoted_prop' attribute to store whether they were originally quoted or not.

closure-compiler/src/com/google/javascript/rhino/Node.java

Line 385 in 6f01d69

public boolean isQuotedString() {

Computed properties/getter/setters are stored differently in the AST.

We probably want to revisit this decision at some point:

1. it's confusing to have different behavior for member functions and regular properties/getters/setters.
2. @concavelenz suggested that (paraphrasing): we want the AST for quoted member functions to maintain the code's original structure, even though they are conceptually similar to computed properties. we also already have a concept of a quoted property.

[lauraharker]

Created internal issue http://b/123769080