EmccCompile: prefer TryRunProcess over RunShellCommand.

[tmds]

A shell is not needed to run emcc.

[maraf]

Thank you @tmds for the contribution!

There are test failures related to the change

src\mono\wasm\build\WasmApp.Common.targets(868,5): error : (NETCORE_ENGINEERING_TELEMETRY=Build) Failed to compile D:\a\_work\1\s\artifacts\bin\microsoft.netcore.app.runtime.browser-wasm\Release\runtimes\browser-wasm\native\src\driver.c -> D:\a\_work\1\s\artifacts\obj\System.Diagnostics.Tracing.Tests\Release\net11.0-browser\browser-wasm\wasm\for-publish\driver.o
An error occurred trying to start process 'D:\a\_work\1\s\src\mono\browser\emsdk\emscripten\emcc' with working directory 'D:\a\_work\1\s\src\libraries\System.Diagnostics.Tracing\tests'. The specified executable is not a valid application for this OS platform.

https://github.com/dotnet/runtime/pull/126150/checks?check_run_id=68749851592

[maraf]

I'm thinking if there wasn't reason to put the command in batch file, something like too long input

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[pavelsavara]

There is problem with too long list of arguments.
This needs to be redesigned to use response files, similar to #123548

[tmds]

I'm thinking if there wasn't reason to put the command in batch file

It seems that on Windows emcc is invokable as emcc because of emcc.bat. You can't Process.Start a bat file. I've added some code to use cmd and a comment to explain.

There is problem with too long list of arguments.
This needs to be redesigned to use response files,

I think this is independent of the changes made here.