GlobalVariableAnalysis not working for global variables only used in the routine.spec e.g., as array dimension

[MichaelSt98]

Problem with GlobalVariableAnalysis as global variables only used in the routine.spec e.g., as array dimension are not captured in uses_symbols. Reason being:

1. transform_subroutine only accounts for routine.body.uses_symbols (and routine.body.defines_symbols), disregarding the routine.spec
2. dataflow_analysis_attached(routine) wouldn't include variables in VariableDeclarations in uses_symbols

Because of (2), this could also result in unwanted behaviour beyond GlobalVariableAnalysis.