Unexpected setting of low_pc during constants::DW_AT_high_pc DebugAddrIndex processing

[mstange]

I think DWARF 5 parsing is broken:

symbolic/symbolic-debuginfo/src/dwarf.rs

Lines 554 to 561 in 33fd1b0

	constants::DW_AT_high_pc => match attr.value() {
	AttributeValue::Addr(addr) => high_pc = Some(addr),
	AttributeValue::DebugAddrIndex(index) => {
	low_pc = Some(self.inner.info.address(self.inner.unit, index)?)
	}
	AttributeValue::Udata(size) => high_pc_rel = Some(size),
	_ => return Err(GimliError::UnsupportedAttributeForm.into()),
	},

This code sets low_pc for DebugAddrIndex values of DW_AT_high_pc. That seems surprising, it should be setting high_pc instead. This is probably just a bug in #326.

Here's the corresponding code from the addr2line crate: https://github.com/gimli-rs/addr2line/blame/62e726615816b865e0998f8b1c6ebaf1645e8334/src/lib.rs#L427-L434

I think DebugAddrIndex is only used in DWARF 5, which is not in wide use yet, which is probably why this hasn't caused many problems yet.