cmd: stop looking for __.(GO)?SYMDEF entries in archives
The Go toolchain stopped creating them before Go 1.3, so no point in
worrying about them today.
History:
- Git commit
250a091 added cmd/ar, which wrote Plan 9 __.SYMDEF
entries into archive files.
- golang.org/cl/
6500117 renamed __.SYMDEF to __.GOSYMDEF. (Notably,
the commit message suggests users need to use Go nm to read symbols,
but even back then the toolchain did nothing with __.(GO)?SYMDEF files
except skip over them.)
- golang.org/cl/
42880043 added the -pack flag to cmd/gc to directly
produce archives by the Go compiler, and did not write __.GOSYMDEF
entries.
- golang.org/cl/
52310044 rewrote cmd/pack in Go, and removed support
for producing __.GOSYMDEF entries.
Change-Id: I255edf40d0d3690e3447e488039fcdef73c6d6b1
Reviewed-on: https://go-review.googlesource.com/19924
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>