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

src/cmd/link/internal/ld/lib.go

@@ -1187,7 +1187,7 @@ func (ctxt *Link) hostlink() {
 
 	switch ctxt.HeadType {
 	case objabi.Hdarwin:
-		if !ctxt.Arch.InFamily(sys.ARM, sys.ARM64) {
+		if machoPlatform == PLATFORM_MACOS {
 			// -headerpad is incompatible with -fembed-bitcode.
 			argv = append(argv, "-Wl,-headerpad,1144")
 		}
@@ -1227,7 +1227,7 @@ func (ctxt *Link) hostlink() {
 	switch ctxt.BuildMode {
 	case BuildModeExe:
 		if ctxt.HeadType == objabi.Hdarwin {
-			if !ctxt.Arch.InFamily(sys.ARM, sys.ARM64) {
+			if machoPlatform == PLATFORM_MACOS {
 				argv = append(argv, "-Wl,-no_pie")
 				argv = append(argv, "-Wl,-pagezero_size,4000000")
 			}