[Manual MIRROR] manual port of the bun migration (#11128)

tools/bootstrap/javascript.bat

@@ -0,0 +1,27 @@
+@echo off
+
+:: Call pwsh if available
+set "powershellCmd=powershell"
+where pwsh >nul 2>nul
+if %errorlevel%==0 (
+    set "powershellCmd=pwsh"
+)
+
+call %powershellCmd% -NoLogo -ExecutionPolicy Bypass -File "%~dp0\javascript_.ps1" Download-Bun
+for /f "tokens=* USEBACKQ" %%s in (`
+    call %powershellCmd% -NoLogo -ExecutionPolicy Bypass -File "%~dp0\javascript_.ps1" Get-Path
+`) do (
+    set "PATH=%%s;%PATH%"
+)
+where bun.exe >nul 2>nul
+if %errorlevel% == 0 (
+    echo | set /p printed_str="Using vendored Bun "
+    call bun.exe --version
+    call bun.exe %*
+    goto exit_with_last_error_level
+)
+echo "javascript.bat: Failed to bootstrap Bun!"
+%COMSPEC% /c exit 1
+
+:exit_with_last_error_level
+if not %errorlevel% == 0 %COMSPEC% /c exit %errorlevel% >nul