private boolean hasCustomCallingConvention() {
		return symbol.getFlags().hasCustomCallingConvention();
	}
Returns true if there is a specific indication that the function has a custom calling
convention.
@return true if positive indication is given
Ghidra/Features/PDB/src/main/java/ghidra/app/util/pdb/pdbapplicator/LabelSymbolApplier.java