RFC: Use section name or <first-symbol>-<offset> as the section start symbol

Hello,

Since llvm-objdump –disassemble is performed symbol by symbol, when dissembling a section that don’t have a symbol at its start address, we need to figure out a proxy symbol name for the address. .plt is a typical case where entry zero has no symbol. Currently llvm-objdump choose to use section name as the proxy symbol across all targets for all sections (including special section like .plt etc.) whereas GNU objdump uses “-”. I submitted a patch to improve the compatibility with GNU.

Before the patch:

.plt:

bar2@plt:

jmp -32 <.plt>

after the patch:

bar2@plt-0x10:

bar2@plt:

jmp -32 bar2@plt-0x10

Fangrui and Peter think the code looks verbose and not aesthetically appealing, suggested we not to adopt GNU behaviour. For disassembly, do we want to exactly match the output of GNU objdump, if there are possible improvements?

https://reviews.llvm.org/D63280