Remove arch brew args

Author: pjcollins

Documentation/building/unix/dependencies.md

@@ -36,12 +36,6 @@ to provide install instructions to obtain the missing dependency, e.g.:
 [Homebrew](https://brew.sh) must be installed and available via `$PATH` in
 order to provision xamarin-android.
 
-When building on Apple Silicon (arm64) machines, use the **arch**(1) command to
-allow Homebrew to be installed:
-
-	% arch -arch x86_64 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
-
-
 <a name="mono-sdk" />
 
 ## Mono MDK

build-tools/xaprepare/xaprepare/ToolRunners/BrewRunner.MacOS.cs

@@ -11,8 +11,6 @@ partial class BrewRunner : ToolRunner
 		static readonly char[] lineSplit = new [] { '\n' };
 
 		bool? needSudo;
-		bool? needArch;
-
 		protected override string DefaultToolExecutableName => GetDefaultExecutableName ();
 		protected override string ToolName                  => "Homebrew";
 
@@ -35,13 +33,10 @@ string GetDefaultExecutableName ()
 					throw new InvalidOperationException ($"BrewRunner does not suppport {Context.Instance.OS.Name}");
 
 				needSudo = os.HomebrewVersion != null && os.HomebrewVersion < sudoVersion;
-				needArch = os.ProcessIsTranslated;
 			}
 
 			if (needSudo ?? false)
 				return "sudo";
-			if (needArch ?? false)
-				return "arch";
 
 			return BrewPath;
 		}
@@ -169,17 +164,7 @@ ProcessRunner GetBrewRunner (bool echoOutput, bool echoError, List<string> argum
 		{
 			ProcessRunner runner = CreateProcessRunner ();
 
-			if ((needSudo ?? false) && (needArch ?? false)) {
-				// So we run `sudo arch -arch x86_64 brew …`
-				runner.AddArgument ("arch");
-			}
-
-			if (needArch ?? false) {
-				runner.AddArgument ("-arch");
-				runner.AddArgument ("x86_64");
-			}
-
-			if ((needSudo ?? false) || (needArch ?? false)) {
+			if ((needSudo ?? false) ) {
 				runner.AddArgument (BrewPath);
 			}