fix(compiler-cli): add missing tslib dependency

[clydin]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/angular/angular/blob/master/CONTRIBUTING.md#commit

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

@angular/compiler-cli require'd tslib in its built output but it was not listed as a dependency and as a result relied on package manager hoisting behavior to function.

What is the new behavior?

tslib is now a direct dependency of the package.

Does this PR introduce a breaking change?

• No

Other information

[mary-poppins]

You can preview 6be8c94 at https://pr27063-6be8c94.ngbuilds.io/.

[alexeagle]

Is there any test we could add to detect this bug?

[angular-automatic-lock-bot]

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