public void setContextRegister(AssemblyPatternBlock ctx) {
		curctx = curctx.combine(ctx);
	}
Set the value of the pseudo context register

<p>
If the provided value has length less than the register, it will be left aligned, and the
remaining bytes will be set to unknown (masked out).

@param val the value of the register
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/sem/AssemblyDefaultContext.java