@Override
	public int getInstructionLength(ContextField cf) {
		return 0; // this is a context field, not an instruction (token) field
	}
Solves expressions of a context register field

<p>
Essentially, this just encodes the goal into the field, if it can be represented in the given
space and format. Otherwise, there is no solution.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/expr/ContextFieldSolver.java