Add +swbt none to remove busy-wait and improve performance (#331)

* Add +swbt none to remove busy-wait and improve performance

Utilizing busy-wait to reduce latency primarily makes sense for
applications that are running as the only node on the machine. So it
doesn't make sense for ElixirLS because there will usually be other
processes running on the machine such as the editor and potentially
other ElixirLS instances.

A blog post that touches on `+swbt none`:
https://www.ably.io/blog/beam-optimization-mqtt/

Also add sbwtdcpu and sbwtdio

Fixes #328

* Add +sbwt none to .bat files also

* Update changelog

Author: axelson

CHANGELOG.md

@@ -5,6 +5,7 @@ Potentially breaking changes:
 
 Improvements:
 - Use ElixirSense's error tolerant parser for document symbols (thanks [Łukasz Samson](https://github.com/lukaszsamson)) [#322](https://github.com/elixir-lsp/elixir-ls/pull/322)
+- Disable busy-wait in BEAM to reduce CPU usage (thanks [Jason Axelson](https://github.com/axelson)) [#331](https://github.com/elixir-lsp/elixir-ls/pull/331)
 
 House keeping:
 - Fix the link in the README to releases (thanks [RJ Dellecese](https://github.com/rjdellecese)) [#312](https://github.com/elixir-lsp/elixir-ls/pull/312)

apps/elixir_ls_utils/priv/debugger.bat

@@ -1,4 +1,4 @@
 @echo off & setlocal enabledelayedexpansion
 
 SET ERL_LIBS=%~dp0;%ERL_LIBS%
-elixir -e "ElixirLS.Debugger.CLI.main()"
+elixir --erl "+sbwt none +sbwtdcpu none +sbwtdio none" -e "ElixirLS.Debugger.CLI.main()"

apps/elixir_ls_utils/priv/language_server.bat

@@ -1,4 +1,4 @@
 @echo off & setlocal enabledelayedexpansion
 
 SET ERL_LIBS=%~dp0;%ERL_LIBS%
-elixir -e "ElixirLS.LanguageServer.CLI.main()"
+elixir --erl "+sbwt none +sbwtdcpu none +sbwtdio none" -e "ElixirLS.LanguageServer.CLI.main()"

apps/elixir_ls_utils/priv/launch.sh

@@ -63,4 +63,4 @@ SCRIPT=$(readlink_f "$0")
 SCRIPTPATH=$(dirname "$SCRIPT")
 export ERL_LIBS="$SCRIPTPATH:$ERL_LIBS"
 
-exec elixir -e "$ELS_SCRIPT"
+exec elixir --erl "+sbwt none +sbwtdcpu none +sbwtdio none"  -e "$ELS_SCRIPT"