@Override
	public boolean isGlobal() {
		return true;
	}
Constructor for HighSymbol which is unattached to a HighFunction
@param id is the unique id to assign
@param nm is the name of the symbol
@param data is an underlying Data object defining the storage and data-type
@param dtmanage is the data-type manager for XML reference
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighCodeSymbol.java