cmd/link/internal/ld: omit bitcode-incompatible flags on iOS simulator
cmd/link/internal/ld: omit bitcode-incompatible flags on iOS simulator

The -Wl,-headerpad, -Wl,-no_pie, -Wl,-pagezero_size flags are
incompatible with the bitcode-related flags used for iOS.

We already omitted the flags on darwin/arm and darwin/arm64; this change
omits the flags on all platforms != macOS so that building for the iOS
simulator works.

Updates #32963

Change-Id: Ic9af0daf01608f5ae0f70858e3045e399de7e95b
Reviewed-on: https://go-review.googlesource.com/c/go/+/205340
Run-TryBot: Elias Naur <1d6e1cf70ec6f9ab28d3ea4b27a49a77654d370e@eliasnaur.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

nawawi/go,CAFxX/go,nawawi/go,akutz/go,akutz/go,cloudflare/go,cloudflare/go,CAFxX/go,cloudflare/go,cloudflare/go,golang/go,cloudflare/go,golang/go,akutz/go,nawawi/go,cloudflare/go,golang/go,nawawi/go,akutz/go,CAFxX/go,nawawi/go,cloudflare/go,nawawi/go,golang/go,akutz/go,akutz/go,nawawi/go,akutz/go,golang/go,golang/go,nawawi/go,CAFxX/go,CAFxX/go,CAFxX/go,CAFxX/go,akutz/go,golang/go,CAFxX/go,cloudflare/go,golang/go