Exception when bell sound is used

[Tyriar]

Repro:

1. Enable bell in vscode
2. Open a terminal
3. Try trigger bell

Uncaught DOMException: Failed to construct 'AudioContext': The number of hardware contexts provided (6) is greater than or equal to the maximum bound (6).
    at SoundManager.playBellSound (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/SoundManager.js:11:34)
    at Terminal.bell (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/Terminal.js:1035:31)
    at InputHandler.bell (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/InputHandler.js:299:24)
    at /Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/InputHandler.js:131:94
    at EscapeSequenceParser.parse (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/EscapeSequenceParser.js:310:25)
    at InputHandler.parse (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/InputHandler.js:200:22)
    at Terminal._innerWrite (/Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/Terminal.js:876:32)
    at /Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/node_modules.asar/vscode-xterm/lib/Terminal.js:858:23

[jerch]

@Tyriar Seems the number of audio contexts one can create has a global hard limit. As a possible workaround Terminal could provide a single AudioContext statically to all instances.