[release/5.0] Add option to prefer 64bit msbuild (#7558)

- cherry-pick of a5dbede / #7531

eng/common/tools.ps1

@@ -371,7 +371,16 @@ function InitializeVisualStudioMSBuild([bool]$install, [object]$vsRequirements =
   }
 
   $msbuildVersionDir = if ([int]$vsMajorVersion -lt 16) { "$vsMajorVersion.0" } else { "Current" }
-  return $global:_MSBuildExe = Join-Path $vsInstallDir "MSBuild\$msbuildVersionDir\Bin\msbuild.exe"
+
+  $local:BinFolder = Join-Path $vsInstallDir "MSBuild\$msbuildVersionDir\Bin"
+  $local:Prefer64bit = if ($vsRequirements.Prefer64bit) { $vsRequirements.Prefer64bit } else { $false }
+  if ($local:Prefer64bit -and (Test-Path(Join-Path $local:BinFolder "amd64"))) {
+    $global:_MSBuildExe = Join-Path $local:BinFolder "amd64\msbuild.exe"
+  } else {
+    $global:_MSBuildExe = Join-Path $local:BinFolder "msbuild.exe"
+  }
+
+  return $global:_MSBuildExe
 }
 
 function InitializeVisualStudioEnvironmentVariables([string] $vsInstallDir, [string] $vsMajorVersion) {
@@ -527,7 +536,7 @@ function GetDefaultMSBuildEngine() {
 
 function GetNuGetPackageCachePath() {
   if ($env:NUGET_PACKAGES -eq $null) {
-    # Use local cache on CI to ensure deterministic build. 
+    # Use local cache on CI to ensure deterministic build.
     # Avoid using the http cache as workaround for https://github.com/NuGet/Home/issues/3116
     # use global cache in dev builds to avoid cost of downloading packages.
     # For directory normalization, see also: https://github.com/NuGet/Home/issues/7968