cmd/link: do not pass -Bsymbolic for PE DLLs

This is only a valid option on ELF. Binutils accepts it, but LLVM
rejects it, so for Windows, it's best to just omit it.

Updates #44250.
Updates #39326.
Updates #38755.
Updates #36439.
Updates #43800.

Change-Id: Iffd2345d757f23dd737e63bd464cd412527077c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/291632


Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>