Update powershell_completions.go

Implement curly bracket technique like spf13#1960

Author: mavaddat

powershell_completions.go

@@ -282,12 +282,12 @@ filter __%[1]s_escapeStringWithSpecialChars {
 $available%[2]s = Get-Command -Name '%[1]s' -All -ErrorAction SilentlyContinue
 
 # Enumerate extant aliases for %[1]s (already set by user)
-$__%[2]sAliases = @()
+${__%[2]sAliases} = @()
 foreach($__%[2]sCmd in $available%[2]s){
     $__%[2]sAliases += Get-Alias | Where-Object { $_.Definition -eq ($__%[2]sCmd | Resolve-Path) }
 }
 # Register args completer for all cmds and aliases
-Register-ArgumentCompleter -CommandName ([array]$available%[2]s.Name + [array]$__%[2]sAliases.Name + @('%[1]s')) -ScriptBlock $__%[2]sCompleterBlock
+Register-ArgumentCompleter -CommandName ([array]$available%[2]s.Name + [array]${__%[2]sAliases}.Name + @('%[1]s')) -ScriptBlock ${__%[2]sCompleterBlock}
 `, name, nameForVar, compCmd,
 		ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
 		ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs, ShellCompDirectiveKeepOrder, activeHelpEnvVar(name)))