long getGP0Value() {
		Symbol symbol = SymbolUtilities.getLabelOrFunctionSymbol(program,
			MIPS_ElfExtension.MIPS_GP0_VALUE_SYMBOL, err -> getLog().appendMsg("MIPS_ELF", err));
		if (symbol == null) {
			return -1;
		}
		return symbol.getAddress().getOffset();
	}
Get the GP0 value (from .reginfo and generated symbol)
@return adjusted GP0 value or -1 if _mips_gp0_value symbol not defined.
Ghidra/Processors/MIPS/src/main/java/ghidra/app/util/bin/format/elf/relocation/MIPS_ElfRelocationContext.java