Add Cos to kernel registry (cpu backend)

[jinjingforever]

Also added a launch.json config to allow debugging in vscode

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This change is 

[tafsiri]

LGTM! Hope the process was relatively smooth.

I'll also let Na take a quick look.

Reviewed 4 of 4 files at r1.
Reviewable status: complete! 1 of 1 approvals obtained (waiting on @lina128 and @tafsiri)

[lina128]

Hi Jing, this looks great, thank you! I left two minor comments, but LGTM overall. And can't wait to try the debugger!

Reviewable status: complete! 2 of 1 approvals obtained (waiting on @jinjingforever and @lina128)

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tfjs-backend-cpu/src/kernels/Cos.ts, line 19 at r1 (raw file):

import {Cos, CosInputs} from '@tensorflow/tfjs-core';
import {KernelConfig} from '@tensorflow/tfjs-core';

Merge above two lines.

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tfjs-backend-cpu/src/kernels/Cos.ts, line 32 at r1 (raw file):

    assertNotComplex(x, 'cos');

    const values = cpuBackend.data.get(x.dataId).values as Float32Array;

as TypedArray, because the values can also be Int32Array.

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tfjs-backend-cpu/src/kernels/Cos.ts, line 33 at r1 (raw file):

    const values = cpuBackend.data.get(x.dataId).values as Float32Array;
    const newValues = new Float32Array(values.length);

Use xSize. const xSize = util.sizeFromShape(x)

[jinjingforever]

Thank you Yannick and Na!

Reviewable status: complete! 2 of 1 approvals obtained (waiting on @lina128)

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tfjs-backend-cpu/src/kernels/Cos.ts, line 19 at r1 (raw file):

Previously, lina128 (Na Li) wrote…

Merge above two lines.

Done.

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tfjs-backend-cpu/src/kernels/Cos.ts, line 32 at r1 (raw file):

Previously, lina128 (Na Li) wrote…

as TypedArray, because the values can also be Int32Array.

Done.

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tfjs-backend-cpu/src/kernels/Cos.ts, line 33 at r1 (raw file):

Previously, lina128 (Na Li) wrote…

Use xSize. const xSize = util.sizeFromShape(x)

Done.