Disambiguate function expression and statement feature descriptions (mdn#9592)

* Distinguish features for function* statements and expressions

* Distinguish `async function` expression and statement features

* Fix bad copy and paste

* Revise `async function*` description

* Rename some function and generator features for consistency

Author: ddbeck

javascript/operators/async_function_expression.json renamed to javascript/operators/async_function_.json

@@ -1,7 +1,7 @@
 {
   "javascript": {
     "operators": {
-      "async_function_expression": {
+      "async_function": {
         "__compat": {
           "description": "<code>async function</code> expression",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/async_function",

javascript/operators/async_function_star.json renamed to javascript/operators/async_generator_function.json

@@ -1,9 +1,9 @@
 {
   "javascript": {
     "operators": {
-      "async_generator_function_expression": {
+      "async_generator_function": {
         "__compat": {
-          "description": "<code>async generator function</code> expression",
+          "description": "<code>async function*</code> expression",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/async_function*",
           "spec_url": "https://tc39.es/ecma262/#sec-async-generator-function-definitions",
           "support": {

javascript/operators/function.json

@@ -3,6 +3,7 @@
     "operators": {
       "function": {
         "__compat": {
+          "description": "<code>function</code> expression",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/function",
           "spec_url": "https://tc39.es/ecma262/#sec-function-definitions",
           "support": {

javascript/operators/function_star.json renamed to javascript/operators/generator_function.json

@@ -1,9 +1,9 @@
 {
   "javascript": {
     "operators": {
-      "function_star": {
+      "generator_function": {
         "__compat": {
-          "description": "<code>function*</code>",
+          "description": "<code>function*</code> expression",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/function*",
           "spec_url": "https://tc39.es/ecma262/#sec-generator-function-definitions",
           "support": {

javascript/statements.json

@@ -3,7 +3,7 @@
     "statements": {
       "async_function": {
         "__compat": {
-          "description": "<code>async function</code>",
+          "description": "<code>async function</code> statement",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/async_function",
           "spec_url": "https://tc39.es/ecma262/#sec-async-function-definitions",
           "support": {
@@ -67,7 +67,7 @@
       },
       "async_generator_function": {
         "__compat": {
-          "description": "<code>async generator function</code>",
+          "description": "<code>async function*</code> statement",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/async_function*",
           "spec_url": "https://tc39.es/ecma262/#sec-async-generator-function-definitions",
           "support": {
@@ -1244,6 +1244,7 @@
       },
       "function": {
         "__compat": {
+          "description": "<code>function</code> statement",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function",
           "spec_url": "https://tc39.es/ecma262/#sec-function-definitions",
           "support": {
@@ -1347,7 +1348,7 @@
       },
       "generator_function": {
         "__compat": {
-          "description": "<code>function*</code>",
+          "description": "<code>function*</code> statement",
           "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function*",
           "spec_url": "https://tc39.es/ecma262/#sec-generator-function-definitions",
           "support": {