public boolean isTypeLocked() {
		return typelock;
	}
If this returns true, this symbol's data-type is "locked", meaning
it is considered unchangeable during decompilation. The data-type
will be forced into the decompiler's model of the function to the extent possible.
@return true if the data-type is considered "locked".
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/HighSymbol.java