Fix rwebaudio bug

[ethanaobrien]

Guidelines

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Description

Fixes a known bug in the rwebaudio (emscripten) driver.

Upon page load, the audio driver, especially on lower end devices, would freeze the page. The console and page would be entirely unresponsive. This fix adds a padding that fixes that issue while preserving audio quality. I dont fully understand why it fixes it, all I can say is that it does

note, you can technically just decrease the blocking check by 1 (RA.bufIndex === RA.numBuffers-1) and not increase the overall amount of buffers, but this causes major audio glitches. I dont understand why decreasing it by 2 and increasing the overall amount of buffers fixes this freezing bug, but it does.

Related Issues

See EmulatorJS/EmulatorJS#416