Reduce size of TypeScript Compiler snapshot (#6809)

This PR is intentionally ugly. It duplicates all of the code in cli/js2/ into
cli/tsc/  ... because it's very important that we all understand that this code
is unnecessarily duplicated in our binary. I hope this ugliness provides the
motivation to clean it up.

The typescript git submodule is removed, because it's a very large repo and
contains all sorts of stuff we don't need. Instead the necessary files are
copied directly into the deno repo. Hence +200k lines.

COMPILER_SNAPSHOT.bin size
```
master         3448139
this branch    3320972
```

Fixes #6812

1 files changed, 44 insertions, 0 deletions

diff --git a/cli/dts/lib.esnext.asynciterable.d.ts b/cli/dts/lib.esnext.asynciterable.d.ts
new file mode 100644
index 000000000..38e12a7ca
--- /dev/null
+++ b/cli/dts/lib.esnext.asynciterable.d.ts
@@ -0,0 +1,44 @@
+/*! *****************************************************************************
+Copyright (c) Microsoft Corporation. All rights reserved. 
+Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+this file except in compliance with the License. You may obtain a copy of the
+License at http://www.apache.org/licenses/LICENSE-2.0  
+ 
+THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
+WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE, 
+MERCHANTABLITY OR NON-INFRINGEMENT. 
+ 
+See the Apache Version 2.0 License for specific language governing permissions
+and limitations under the License.
+***************************************************************************** */
+
+
+
+/// <reference no-default-lib="true"/>
+
+
+/// <reference lib="es2015.symbol" />
+/// <reference lib="es2015.iterable" />
+
+interface SymbolConstructor {
+    /**
+     * A method that returns the default async iterator for an object. Called by the semantics of
+     * the for-await-of statement.
+     */
+    readonly asyncIterator: symbol;
+}
+
+interface AsyncIterator<T> {
+    next(value?: any): Promise<IteratorResult<T>>;
+    return?(value?: any): Promise<IteratorResult<T>>;
+    throw?(e?: any): Promise<IteratorResult<T>>;
+}
+
+interface AsyncIterable<T> {
+    [Symbol.asyncIterator](): AsyncIterator<T>;
+}
+
+interface AsyncIterableIterator<T> extends AsyncIterator<T> {
+    [Symbol.asyncIterator](): AsyncIterableIterator<T>;
+}
\ No newline at end of file