Add static methods (#25)

Add a vector of static methods, getters, and setters to the declaration
of a constructor function.

Author: tlively

proposals/custom-descriptors/Overview.md

@@ -586,24 +586,23 @@ descriptordata  ::= n:name (if n = 'descriptors')
 descriptorentry ::= 0x00 importentry
                   | 0x01 declentry
 
-importentry     ::= importname:name descconfig
+importentry      ::= importname:name descconfig
 
-declentry       ::= protoconfig descconfig
+declentry        ::= protoconfig descconfig
 
-protoconfig     ::= v:vec(descindex) (if |v| <= 1)
+protoconfig      ::= v:vec(descindex) (if |v| <= 1)
 
-descconfig      ::= exportnames vec(methodconfig)
+descconfig       ::= exportnames:vec(name) methods:vec(methodconsconfig)
 
-exportnames     ::= vec(name)
+methodnames      ::= methodname:name exportname:name
 
-methodconfig    ::= kind:methodkind
-                    methodname:name
-                    exportname:name
+methodconfig     ::= 0x00 methodnames => method
+                   | 0x01 methodnames => getter
+                   | 0x02 methodnames => setter
+
+methodconsconfig ::= methodconfig
+                   | 0x03 methodnames vec(methodconfig) => constructor
 
-methodkind      ::= 0x00 => method
-                  | 0x01 => getter
-                  | 0x02 => setter
-                  | 0x03 => constructor
 ```
 
 The descriptors custom section starts with a version number,
@@ -624,12 +623,14 @@ by including multiple descriptors sections.
 Following the `modulename` is a sequence of `descriptorentry`,
 each of which describes a declared `DescriptorOptions` value or an imported prototype
 for use in the prototype chain of subsequent declared `DescriptorOptions`.
-A declaration value can optionally specify the index of a previous entry
+A declaration can optionally specify the index of a previous entry
 to provide the parent in the configured prototype chain.
 If the previous entry is an `importentry`, the `modulename` and `importname`
 are used to look up the prototype in the imports object.
 Otherwise, if the previous entry is a `declentry`,
 the prototype is looked up from the declared `DescriptorOptions`.
+If there is no configured parent,
+the parent of the new prototype is `Object.prototype`.
 
 Each declared descriptor has a vector of export names.
 After the descriptor is created,
@@ -648,9 +649,9 @@ describing the methods that should be attached to the prototype
 after instantiation.
 Each configured method can be either a
 normal method, a getter, a setter, or a constructor.
-Methods also have two associated names: the first their property name
-in the configured prototype and the second
-the name of the exported function they wrap.
+Methods each have two associated names:
+the first is their property name in the configured prototype
+and the second is the name of the exported function they wrap.
 
 All methods pass the receiver as the first argument:
 
@@ -670,9 +671,15 @@ function methodname() { return exports[exportname](...arguments); }
 
 Furthermore, they are not installed on the configured prototype.
 Instead, they are added to the `exports` object.
-The configured prototype is added as the `prototype` property of the generated function
+The configured prototype is added as the `prototype` property of the generated constructor function
 and the generated function is added as the `constructor` property of the configured prototype.
 
+Constructor declarations also contain additional methods, getters, and setters
+that will be installed as properties of the constructor itself
+rather than the prototype.
+Like the constructor function itself,
+these "static" methods, getters, and setters do not pass their receiver as an argument.
+
 ### Instantiation
 
 When constructing a WebAssembly instance,