Fix literal type annotation argument number (#7706)

Added the value argument to the visitors of flow literal type
annotations.
Literal type annotations need a value since they work very much like
primitive literals in normal JavaScript.

Fixes #7697

packages/babel-types/README.md

@@ -183,14 +183,14 @@ Aliases: `Expression`, `Pureish`, `Literal`, `Immutable`
 
 ### booleanLiteralTypeAnnotation
 ```javascript
-t.booleanLiteralTypeAnnotation()
+t.booleanLiteralTypeAnnotation(value)
 ```
 
 See also `t.isBooleanLiteralTypeAnnotation(node, opts)` and `t.assertBooleanLiteralTypeAnnotation(node, opts)`.
 
 Aliases: `Flow`, `FlowType`
 
- - `value`: `boolean` (default: `null`)
+ - `value`: `boolean` (required)
 
 ---
 
@@ -1408,14 +1408,14 @@ Aliases: `Flow`, `FlowType`
 
 ### numberLiteralTypeAnnotation
 ```javascript
-t.numberLiteralTypeAnnotation()
+t.numberLiteralTypeAnnotation(value)
 ```
 
 See also `t.isNumberLiteralTypeAnnotation(node, opts)` and `t.assertNumberLiteralTypeAnnotation(node, opts)`.
 
 Aliases: `Flow`, `FlowType`
 
- - `value`: `number` (default: `null`)
+ - `value`: `number` (required)
 
 ---
 
@@ -1776,14 +1776,14 @@ Aliases: `Expression`, `Pureish`, `Literal`, `Immutable`
 
 ### stringLiteralTypeAnnotation
 ```javascript
-t.stringLiteralTypeAnnotation()
+t.stringLiteralTypeAnnotation(value)
 ```
 
 See also `t.isStringLiteralTypeAnnotation(node, opts)` and `t.assertStringLiteralTypeAnnotation(node, opts)`.
 
 Aliases: `Flow`, `FlowType`
 
- - `value`: `string` (default: `null`)
+ - `value`: `string` (required)
 
 ---
 

packages/babel-types/src/definitions/flow.js

@@ -26,6 +26,7 @@ defineType("BooleanTypeAnnotation", {
 });
 
 defineType("BooleanLiteralTypeAnnotation", {
+  builder: ["value"],
   aliases: ["Flow", "FlowType"],
   fields: {
     value: validate(assertValueType("boolean")),
@@ -239,6 +240,7 @@ defineType("NullableTypeAnnotation", {
 });
 
 defineType("NumberLiteralTypeAnnotation", {
+  builder: ["value"],
   aliases: ["Flow", "FlowType"],
   fields: {
     value: validate(assertValueType("number")),
@@ -329,6 +331,7 @@ defineType("QualifiedTypeIdentifier", {
 });
 
 defineType("StringLiteralTypeAnnotation", {
+  builder: ["value"],
   aliases: ["Flow", "FlowType"],
   fields: {
     value: validate(assertValueType("string")),