cmd/link/internal/ld: consider alternative linkers in linkerFlagSupported

CL 235017 is about to change the default Android linker to lld. lld doesn't
support the --compress-debug-sections=zlib-gnu flag, but linkerFlagSupported
doesn't take any alternative linkers specified with -fuse-ld into account.

Updates #38838

Change-Id: I5f7422c06d40dedde2e4b070fc48398e8f822190
Reviewed-on: https://go-review.googlesource.com/c/go/+/235157


Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>