cmd/compile,cmd/asm: dump sym ABI versions for -S=2

When -S=2 is in effect for the compiler/assembler, include symbol ABI
values for defined symbols and relocations. This is intended to help
make it easier to distinguish between a symbol and its ABI wrapper.

Change-Id: Ifbf71372392075f15363b40e882b2132406b7d6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/255718


Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>