Add host to list of initialized variable

Author: Quoc Truong

Engine/SpecialVars.cs

@@ -140,6 +140,7 @@ internal enum PreferenceVariable
             Confirm = 14,
         }
 
+        internal const string Host = "Host";
         internal const string HistorySize = "MaximumHistoryCount";
         internal const string OutputEncoding = "OutputEncoding";
         internal const string NestedPromptLevel = "NestedPromptLevel";
@@ -159,6 +160,7 @@ internal enum PreferenceVariable
 
         internal static readonly string[] OtherInitializedVariables = new string[]
                                                                 {
+                                                                    Host,
                                                                     HistorySize,
                                                                     OutputEncoding,
                                                                     NestedPromptLevel,

Tests/Rules/AvoidGlobalOrUnitializedVarsNoViolations.ps1

@@ -9,6 +9,9 @@ function Test {
 
 $a = 3;
 
+#should not raise error
+$Host
+
 "hi there!" -match "hi" | Out-Null;
 $matches[0];