Bump version number to 4.0 (#38215)

Author: DanielRosenwasser

package.json

@@ -2,7 +2,7 @@
     "name": "typescript",
     "author": "Microsoft Corp.",
     "homepage": "https://www.typescriptlang.org/",
-    "version": "3.9.0",
+    "version": "4.0.0",
     "license": "Apache-2.0",
     "description": "TypeScript is a language for application scale JavaScript development",
     "keywords": [

src/compiler/corePublic.ts

@@ -1,7 +1,7 @@
 namespace ts {
     // WARNING: The script `configurePrerelease.ts` uses a regexp to parse out these values.
     // If changing the text in this section, be sure to test `configurePrerelease` too.
-    export const versionMajorMinor = "3.9";
+    export const versionMajorMinor = "4.0";
     /** The version of the TypeScript compiler release */
     export const version = `${versionMajorMinor}.0-dev`;
 

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -14,7 +14,7 @@ and limitations under the License.
 ***************************************************************************** */
 
 declare namespace ts {
-    const versionMajorMinor = "3.9";
+    const versionMajorMinor = "4.0";
     /** The version of the TypeScript compiler release */
     const version: string;
     /**

tests/baselines/reference/api/typescript.d.ts

@@ -14,7 +14,7 @@ and limitations under the License.
 ***************************************************************************** */
 
 declare namespace ts {
-    const versionMajorMinor = "3.9";
+    const versionMajorMinor = "4.0";
     /** The version of the TypeScript compiler release */
     const version: string;
     /**