Win: Use @ instead of echo off in vssetup.cmd

`echo off` affects the batch files called from this file as well.

Author: nobu

win32/vssetup.cmd

@@ -1,27 +1,27 @@
-@echo off
-setlocal ENABLEEXTENSIONS
+@setlocal ENABLEEXTENSIONS
+::- do not `echo off` that affects the called batch files
 
 ::- check for vswhere
-set vswhere=%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe
-if not exist "%vswhere%" (
+@set vswhere=%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe
+@if not exist "%vswhere%" (
   echo 1>&2 vswhere.exe not found
   exit /b 1
 )
 
 ::- find the latest build tool and its setup batch file.
-set VSDEVCMD=
-for /f "delims=" %%I in ('"%vswhere%" -products * -latest -property installationPath') do (
+@set VSDEVCMD=
+@for /f "delims=" %%I in ('"%vswhere%" -products * -latest -property installationPath') do @(
   set VSDEVCMD=%%I\Common7\Tools\VsDevCmd.bat
 )
-if not defined VSDEVCMD (
+@if not defined VSDEVCMD (
   echo 1>&2 Visual Studio not found
   exit /b 1
 )
 
 ::- default to the current processor.
-set arch=%PROCESSOR_ARCHITECTURE%
+@set arch=%PROCESSOR_ARCHITECTURE%
 ::- `vsdevcmd.bat` requires arch names to be lowercase
-for %%i in (a b c d e f g h i j k l m n o p q r s t u v w x y z) do @(
+@for %%i in (a b c d e f g h i j k l m n o p q r s t u v w x y z) do @(
   call set arch=%%arch:%%i=%%i%%
 )
-echo on && endlocal && "%VSDEVCMD%" -arch=%arch% -host_arch=%arch% %*
+@(endlocal && "%VSDEVCMD%" -arch=%arch% -host_arch=%arch% %*)