private boolean isFunctionPointer(Listing listing, Address fromAddress) {
		Data fromData = listing.getDataContaining(fromAddress);
		if (fromData != null) {
			int offset = (int) fromAddress.subtract(fromData.getAddress());
			Data primitiveAt = fromData.getPrimitiveAt(offset);
			DataType dataType3 = primitiveAt.getDataType();
			if (dataType3 instanceof Pointer) {
				Pointer pointer = (Pointer) dataType3;
				DataType pointerDataType = pointer.getDataType();
				if (pointerDataType instanceof FunctionDefinition) {
					return true;
				}
			}
		}
		return false;
	}
Check for any jumps to Externals (manufactured labels).
Any externals directly jumped to should be looked at as a call.

Note: this shouldn't affect jumps in thunks, but beware...
@param monitor
@throws CancelledException
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/analysis/OperandReferenceAnalyzer.java