Add hooks to support reading of section definition symbol aux data
(including COMDAT information) from the aux symbols associated with
section definition symbols. The COFF symbol array made available by
"pe.File" includes entries for aux symbols, but doesn't expose their
structure (since it varies depending on the type of aux symbol). This
patch adds a function for returning a specific class of aux symbol
("type 5") that immediately follows a COFF symbol corresponding to a
section definition.
Updates #35006.
Updates #51868.
Change-Id: I21fcc057150f7a3c64f01a5961aabca0fa43399e
Reviewed-on: https://go-review.googlesource.com/c/go/+/394534
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
