PR Summary

This PR fixes the following longstanding issue:#1300 (Global variables are erroneously reported as "never used")

The issue exists becauseHelper.IsVariableGlobalOrEnvironment uses anAst to key intoVariableAnalysisDictionary, callingVariableAnalysis.IsGlobalOrEnvironment on the value returned to determine whether or not the variable is a global. However, in some cases, the key does not exist in the dictionary, resulting in the method returningfalse. Fortunately,VariableAnalysis.IsGlobalOrEnvironment depends on no instance members, instead relying solely on the properties ofVariableExpressionAst, which is passed in. As such,VariableAnalysis.IsGlobalOrEnvironment can be madestatic with no consequence, allowingHelper.IsVariableGlobalOrEnvironment to call the method without the dictionary operations.

Also of note, the current implementation is somewhat redundant, withUseDeclaredVarsMoreThanAssignments.AnalyzeScriptBlockAst checkingVariablePath.DriveName separately, which is why the issue does not affect environment variables despiteVariableAnalysis.IsGlobalOrEnvironment erroneously returningfalse in some cases.

PR Checklist

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