cmd/internal/objfile: break out dissassemblers to another package

Currently, cmd/internal/objfile provides dissassembly routines for
various architectures, which depend on dissassemblers from x/arch.
cmd/internal/objfile is imported in tools that need dissassembly
(objdump, pprof) and tools that don't need dissassembly (nm,
addr2line). Adding/improving disassembly support for more
architectures can cause binary size increase, and for some tools
(nm, addr2line) it is not necessary.

This CL breaks out dissassembly routines to a different package,
which is only imported in tools that need dissassembly. Other
tools can depend on cmd/internal/objfile without the disassembly
code from x/arch.

This reduces binary sizes for those tools. On darwin/arm64,

                                 old         new
cmd/addr2line                  4554418     3648882   -20%
cmd/addr2line (-ldflags=-w)    3464626     2641650   -24%
cmd/nm                         4503874     3616722   -20%
cmd/nm (-ldflags=-w)           3430594     2609490   -24%

For #70699.

Change-Id: Ie45d5d5c5500c5f3882e8b3c4e6eb81f0d815292
Reviewed-on: https://go-review.googlesource.com/c/go/+/634916
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>

0 files changed, 0 insertions, 0 deletions